Mapping Mountains – Significant Height Revisions – The Fours - The 400m Hills of England

 

The Fours – The 400m Hills of England - Significant Height Revisions

The Fours - The 400m Hills of England are the English hills at and above 400m and below 500m in height that have 30m minimum drop.  Accompanying the main list are three sub lists; these are the 400m Sub-Fours, 390m Sub-Fours and 390m Double Sub-Fours.  With their criteria detailed in the Change Registers which are linked in the above titles.

The list is co-authored by Myrddyn Phillips and Aled Williams and the posts that have appeared on Mapping Mountains detailing the Significant Height Revisions to the main P30 list and the sub lists appear below presented chronologically in receding order.

Postscript:  On the 10^th July 2024 the final group of hills in the updated version of this list were published on the Mapping Mountains site.  It was also announced that the sub hills accompanying the main listing of The Fours – The 400m Hills of England now take in just one category, this category is entitled the Sub-Fours. 

Therefore, the 390m Sub-Fours and 390m Double Sub-Fours have been dispensed with and the criteria for the 400m Sub-Fours that included English hills at and above 400m and below 500m in height that have 20m and more and below 30m of drop, have been amended to include English hills at and above 400m and below 500m in height that have 15m and more and below 30m of drop and their title changed to the Sub-Fours.

Mapping Mountains - Significant Height Revisions - The Fours - The 400m Hills of England

Gib Torr Rocks (SK 018 647) - 44th significant height revision

 

There has been a Significant Height Revision to a hill that is listed in the The Fours – The 400m Hills of England, with the summit height, col height and their locations, the drop and status of the hill derived from LIDAR analysis conducted by Myrddyn Phillips. 

LIDAR image of Gib Torr Rocks (SK 018 647)

The criteria for the list that this height revision applies to are:

The Fours – The 400m Hills of England - English hills at or above 400m and below 500m in height that have 30m minimum drop, accompanying the main list is a sub list entitled the Sub-Fours, the criteria for which are all English hills at or above 400m and below 500m in height that have 15m or more and below 30m of drop.  The list is co-authored by Myrddyn Phillips and Aled Williams and is available to download in Google Doc format from the Mapping Mountains site.

The Fours - The 400m Hills of England by Myrddyn Phillips and Aled Williams

The name the hill is listed by is Gib Torr Rocks, and it is adjoined to the Axe Edge group of hills, which are situated in the Peak District, and it is positioned with minor roads to its north, west, south and east, and the A53 road to its south-east, and has the town of Leek towards the south south-west.

When the Introduction to the first group of hills for the updated and revised listing of the The Fours – The 400m Hills of England was published by Mapping Mountains on the 10^th September 2022, it was announced that the accompanying sub lists were being revised with the two 390m categories dispensed with and the criteria and name of the 400m Sub-Fours revised.  The one accompanying sub list is now named the Sub-Fours with its criteria being all English hills 400m and above and below 500m in height that have 15m and more and below 30m of drop.

Prior to this revision this hill was listed with an estimated c 17m of drop, based on an estimated c 415m summit height and an estimated c 398m col height, with both heights based on interpolation of 5m contouring that appears on the Ordnance Survey 1:25,000 Explorer map. 

Extract from the Ordnance Survey 1:25,000 Explorer map

However, it was not until LIDAR became available that the details for this hill could be accurately re-assessed.  The LIDAR (Light Detection & Ranging) technique produced highly accurate height data that is now freely available for much of England and Wales. 

LIDAR summit image of Gib Torr Rocks (SK 018 647)

LIDAR analysis gives the summit height of this hill as 417.3m and when compared to its originally listed height this comes within the parameters of the Significant Height Revisions used within this page heading, these parameters are:

The term Significant Height Revisions applies to any listed hill whose interpolated height and Ordnance Survey, Harvey or other interactive map summit spot height has a 2m or more discrepancy when compared to the survey result produced by the Trimble GeoXH 6000 or analysis of data produced via LIDAR.  Also included are hills whose summit map data is missing an uppermost ring contour when compared with the data produced by the Trimble or by LIDAR analysis.

Therefore, the new listed summit height of this hill is 417.3m and this was derived from LIDAR analysis, this is 2.3m higher than the originally listed summit height, which was based on interpolation of the uppermost ring contour that appears on the Ordnance Survey 1:25,000 Explorer map. 

 

The full details for the hill are:

Group:  Axe Edge

Name:  Gib Torr Rocks

OS 1:50,000 map:  119

Summit Height (New Height):  417.3m (LIDAR)

Summit Grid Reference:  SK 01803 64749 (LIDAR)

Col Height:  398.5m (LIDAR)

Col Grid Reference:  SK 01797 64842 (LIDAR)

Drop:  18.8m (LIDAR)

 

Myrddyn Phillips and Aled Williams (December 2025)

Mapping Mountains - Significant Height Revisions - The Fours - The 400m Hills of England

Eldon Hill Quarries (SK 115 815) - 43rd significant height revision

Hill Reclassifications post for Eldon Hill Quarries

 

There has been a Significant Height Revision to a hill that is listed in the The Fours – The 400m Hills of England, with the summit height, col height and their locations, the drop and status of the hill derived from LIDAR analysis conducted by Myrddyn Phillips. 

LIDAR image of Eldon Hill Quarries (SK 115 815)

The criteria for the list that this height revision applies to are:

The Fours – The 400m Hills of England - English hills at or above 400m and below 500m in height that have 30m minimum drop, accompanying the main list is a sub list entitled the Sub-Fours, the criteria for which are all English hills at or above 400m and below 500m in height that have 15m or more and below 30m of drop.  The list is co-authored by Myrddyn Phillips and Aled Williams and is available to download in Google Doc format from the Mapping Mountains site.

The Fours - The 400m Hills of England by Myrddyn Phillips and Aled Williams

The name the hill is listed by is Eldon Hill Quarries, and it is adjoined to the Kinder Scout group of hills, which are situated in the Peak District, and it is positioned with a minor road to its north-west and the A623 road to its south, and has the town of Chapel-en-le-Frith towards the west.

When the Introduction to the first group of hills for the updated and revised listing of the The Fours – The 400m Hills of England was published by Mapping Mountains on the 10^th September 2022, it was announced that the accompanying sub lists were being revised with the two 390m categories dispensed with and the criteria and name of the 400m Sub-Fours revised.  The one accompanying sub list is now named the Sub-Fours with its criteria being all English hills 400m and above and below 500m in height that have 15m and more and below 30m of drop. 

Extract from the Ordnance Survey 1:25,000 Explorer map

Prior to this revision this hill was not listed, with subsequent interpolation giving it an estimated c 16m of drop, based on the 413m summit spot height that appears on the DataMapWales and an estimated c 397m col height, based on interpolation of 5m contouring between 395m – 400m. 

Extract from the DataMapWales

However, it was not until LIDAR became available that the details for this hill could be accurately re-assessed.  The LIDAR (Light Detection & Ranging) technique produced highly accurate height data that is now freely available for much of England and Wales. 

LIDAR summit image of Eldon Hill Quarries (SK 115 815)

LIDAR analysis gives the summit height of this hill as 415.9m and when compared to its originally listed height this comes within the parameters of the Significant Height Revisions used within this page heading, these parameters are:

The term Significant Height Revisions applies to any listed hill whose interpolated height and Ordnance Survey, Harvey or other interactive map summit spot height has a 2m or more discrepancy when compared to the survey result produced by the Trimble GeoXH 6000 or analysis of data produced via LIDAR.  Also included are hills whose summit map data is missing an uppermost ring contour when compared with the data produced by the Trimble or by LIDAR analysis.

Therefore, the new listed summit height of this hill is 415.9m and this was derived from LIDAR analysis, this is 2.9m higher than the originally listed summit height, which was based on 413m spot height that appears on the DataMapWales. 

 

The full details for the hill are:

Group:  Kinder Scout

Name:  Eldon Hill Quarries

OS 1:50,000 map:  110

Summit Height (New Height):  415.9m (LIDAR)

Summit Grid Reference:  SK 11562 81552 (LIDAR)

Col Height:  396.7m (LIDAR)

Col Grid Reference:  SK 11624 81555 (LIDAR)

Drop:  19.1m (LIDAR)

 

Myrddyn Phillips and Aled Williams (December 2025)

Mapping Mountains - Significant Height Revisions - The Fours - The 400m Hills of England

Kilnsey Moor (SD 948 669) - 42nd significant height revision

Hill Reclassifications post for Kilnsey Moor

 

There has been a Significant Height Revision to a hill that was provisionally listed in the The Fours – The 400m Hills of England, with the summit height, col height and their locations, the drop and status of the hill derived from LIDAR analysis conducted by Myrddyn Phillips. 

LIDAR image of Kilnsey Moor (SD 948 669)

The criteria for the list that this height revision applies to are:

The Fours – The 400m Hills of England - English hills at or above 400m and below 500m in height that have 30m minimum drop, accompanying the main list is a sub list entitled the Sub-Fours, the criteria for which are all English hills at or above 400m and below 500m in height that have 15m or more and below 30m of drop.  The list is co-authored byMyrddyn Phillips and Aled Williams and is available to download in Google Doc format from the Mapping Mountains site.

The Fours - The 400m Hills of England by Myrddyn Phillips and Aled Williams

The name the hill is listed by is Kilnsey Moor, and it is adjoined to the Pen y Ghent group of hills, which are situated in the Pennines of northern England, and it is positioned with a minor road to its south, and the B6160 road to its east, and has the village of Threshfield towards the south-east.

When the Introduction to the first group of hills for the updated and revised listing of the The Fours – The 400m Hills of England was published by Mapping Mountains on the 10^th September 2022, it was announced that the accompanying sub lists were being revised with the two 390m categories dispensed with and the criteria and name of the 400m Sub-Fours revised.  The one accompanying sub list is now named the Sub-Fours with its criteria being all English hills 400m and above and below 500m in height that have 15m and more and below 30m of drop.

Prior to this revision this hill was listed with 15m of drop, based on the 468m summit spot height that appeared on the Ordnance Survey Vector Map Local hosted on the Geograph website and which was entitled the Interactive Coverage Map and the 453m col spot height that appears on the Ordnance Survey 1:25,000 Explorer map. 

Extract from the Ordnance Survey 1:25,000 Explorer map

However, it was not until LIDAR became available that the details for this hill could be accurately re-assessed.  The LIDAR (Light Detection & Ranging) technique produced highly accurate height data that is now freely available for much of England and Wales. 

LIDAR summit image of Kilnsey Moor (SD 948 669)

LIDAR analysis gives the height of this hill as 463.4m, and when compared to its originally listed summit height this comes within the parameters of the Significant Height Revisions used within this page heading, these parameters are:

The term Significant Height Revisions applies to any listed hill whose interpolated height and Ordnance Survey, Harvey or other interactive map summit spot height has a 2m or more discrepancy when compared to the survey result produced by the Trimble GeoXH 6000 or analysis of data produced via LIDAR.  Also included are hills whose summit map data is missing an uppermost ring contour when compared with the data produced by the Trimble or by LIDAR analysis.

Therefore, the new listed summit height of this hill is 463.4m and this was derived from LIDAR analysis, this is 4.6m lower than the originally listed summit height, which was based on 468m spot height that appeared on the Ordnance Survey Vector Map Local hosted on the Geograph website and which was entitled the Interactive Coverage Map. 

 

The full details for the hill are:

Group:  Pen y Ghent

Name:  Kilnsey Moor

OS 1:50,000 map:  98

Summit Height (New Heigt):  463.4m (LIDAR)

Summit Grid Reference:  SD 94838 66954 (LIDAR)

Col Height:  453.4m (LIDAR)

Col Grid Reference:  SD 94926 67281 (LIDAR)

Drop:  9.9m (LIDAR)

 

Myrddyn Phillips and Aled Williams (October 2025)

Mapping Mountains - Significant Height Revisions - The Fours - The 400m Hills of England

Galloway Pasture (SE 109 632) - 41st significant height revision

 

There has been a Significant Height Revision to a hill that is listed in the The Fours – The 400m Hills of England, with the summit height, col height and their locations, the drop and status of the hill derived from LIDAR analysis conducted by Myrddyn Phillips. 

LIDAR image of Galloway Pasture (SE 109 632)

The criteria for the list that this height revision applies to are:

The Fours – The 400m Hills of England - English hills at or above 400m and below 500m in height that have 30m minimum drop, accompanying the main list is a sub list entitled the Sub-Fours, the criteria for which are all English hills at or above 400m and below 500m in height that have 15m or more and below 30m of drop.  The list is co-authored by Myrddyn Phillips and Aled Williams and is available to download in Google Doc format from the Mapping Mountains site.

The Fours - The 400m Hills of England by Myrddyn Phillips and Aled Williams

The name the hill is listed by is Galloway Pasture, and it is adjoined to the Whernside group of hills, which are situated in the Pennines of northern England, and it is positioned with the B6265 road to its north and a minor road to its east, and has the town of Pateley Bridge towards the east north-east.

When the Introduction to the first group of hills for the updated and revised listing of the The Fours – The 400m Hills of England was published by Mapping Mountains on the 10^th September 2022, it was announced that the accompanying sub lists were being revised with the two 390m categories dispensed with and the criteria and name of the 400m Sub-Fours revised.  The one accompanying sub list is now named the Sub-Fours with its criteria being all English hills 400m and above and below 500m in height that have 15m and more and below 30m of drop.

Prior to this revision this hill was listed with an estimated c 19m of drop, based on the 425m summit spot height that appears on the Ordnance Survey 1:25,000 Explorer map and an estimated c 406m col height, based on interpolation of 10m contouring between 400m – 410m. 

Extract from the Ordnance Survey 1:25,000 Explorer map

However, it was not until LIDAR became available that the details for this hill could be accurately re-assessed.  The LIDAR (Light Detection & Ranging) technique produced highly accurate height data that is now freely available for much of England and Wales. 

LIDAR summit image of Galloway Pasture (SE 109 632)

LIDAR analysis gives the height of this hill as 427.5m and when compared to its originally listed summit height this comes within the parameters of the Significant Height Revisions used within this page heading, these parameters are:

The term Significant Height Revisions applies to any listed hill whose interpolated height and Ordnance Survey, Harvey or other interactive map summit spot height has a 2m or more discrepancy when compared to the survey result produced by the Trimble GeoXH 6000 or analysis of data produced via LIDAR.  Also included are hills whose summit map data is missing an uppermost ring contour when compared with the data produced by the Trimble or by LIDAR analysis.

Therefore, the new listed summit height of this hill is 427.5m and this was derived from LIDAR analysis, this is 2.5m higher than the originally listed summit height, which was based on 425m spot height that appears on the Ordnance Survey 1:25,000 Explorer map. 

 

The full details for the hill are:

Group:  Whernside

Name:  Galloway Pasture

OS 1:50,000 map:  99

Summit Height (New Height):  427.5m (LIDAR)

Summit Grid Reference:  SE 10920 63236 (LIDAR)

Col Height:  409.7m (LIDAR)

Col Grid Reference:  SE 10918 63764 (LIDAR)

Drop:  17.9m (LIDAR)

 

Myrddyn Phillips and Aled Williams (September 2025)

Mapping Mountains - Significant Height Revisions - The Fours - The 400m Hills of England

Great Wegber (SD 994 912) - 40th significant height revision

Hill Reclassifications post for Great Wegber

Summit Relocations post for Great Wegber

 

There has been a Significant Height Revision to a hill that has been excluded from the listing of the The Fours – The 400m Hills of England, with the summit height, col height and their locations, the drop and status of the hill derived from LIDAR analysis conducted by Myrddyn Phillips. 

LIDAR image of Great Wegber (SD 994 912)

The criteria for the list that this height revision applies to are:

The Fours – The 400m Hills of England - English hills at or above 400m and below 500m in height that have 30m minimum drop, accompanying the main list is a sub list entitled the Sub-Fours, the criteria for which are all English hills at or above 400m and below 500m in height that have 15m or more and below 30m of drop.  The list is co-authored by Myrddyn Phillips and Aled Williams and is available to download in Google Doc format from the Mapping Mountains site.

The Fours - The 400m Hills of England by Myrddyn Phillips and Aled Williams

The name the hill is listed by is Great Wegber, and it is adjoined to the Great Shunner Fell group of hills, which are situated in the Pennines of northern England, and it is positioned with minor roads to its west, south and east, with the A684 road farther to its south, and has the town of Leyburn towards the east.

When the Introduction to the first group of hills for the updated and revised listing of the The Fours – The 400m Hills of England was published by Mapping Mountains on the 10^th September 2022, it was announced that the accompanying sub lists were being revised with the two 390m categories dispensed with and the criteria and name of the 400m Sub-Fours revised.  The one accompanying sub list is now named the Sub-Fours with its criteria being all English hills 400m and above and below 500m in height that have 15m and more and below 30m of drop.

Prior to this revision this hill was listed with an estimated c 15m of drop, based on an estimated c 421 summit height and an estimated c 406m col height, with both heights based on interpolation of 10m contouring that appears on the Ordnance Survey 1:25,000 Explorer map. 

Extract from the Ordnance Survey 1:25,000 Explorer map

However, it was not until LIDAR became available that the details for this hill could be accurately re-assessed.  The LIDAR (Light Detection & Ranging) technique produced highly accurate height data that is now freely available for much of England and Wales. 

LIDAR summit image of Great Wegber (SD 994 912)

LIDAR analysis gives the height of this hill as 418.7m and when compared to its originally listed summit height this comes within the parameters of the Significant Height Revisions used within this page heading, these parameters are:

The term Significant Height Revisions applies to any listed hill whose interpolated height and Ordnance Survey, Harvey or other interactive map summit spot height has a 2m or more discrepancy when compared to the survey result produced by the Trimble GeoXH 6000 or analysis of data produced via LIDAR.  Also included are hills whose summit map data is missing an uppermost ring contour when compared with the data produced by the Trimble or by LIDAR analysis.

Therefore, the new listed summit height of this hill is 418.7m and this was derived from LIDAR analysis, this is 2.3m lower than the originally listed c 421m summit height, which was based on interpolation of the uppermost 420m ring contour that appears on the Ordnance Survey 1:25,000 Explorer map. 

 

The full details for the hill are:

Group:  Great Shunner Fell

Name:  Great Wegber

OS 1:50,000 map:  98

Summit Height (New Height):  418.7m (LIDAR)

Summit Grid Reference:  SD 99490 91225 (LIDAR)

Col Height:  406.1m (LIDAR)

Col Grid Reference:  SD 99350 91694 (LIDAR)

Drop:  12.6m (LIDAR)

 

Myrddyn Phillips and Aled Williams (September 2025)

Mapping Mountains - Significant Height Revisions - The Fours - The 400m Hills of England

Owlands Barf (NZ 049 017) - 39th significant height revision

 

There has been a Significant Height Revision to a hill that is listed in the The Fours – The 400m Hills of England, with the summit height, col height and their locations, the drop and status of the hill derived from LIDAR analysis conducted by Myrddyn Phillips. 

LIDAR image of Owlands Barf (NZ 049 017)

The criteria for the list that this height revision applies to are:

The Fours – The 400m Hills of England - English hills at or above 400m and below 500m in height that have 30m minimum drop, accompanying the main list is a sub list entitled the Sub-Fours, the criteria for which are all English hills at or above 400m and below 500m in height that have 15m or more and below 30m of drop.  The list is co-authored by Myrddyn Phillips and Aled Williams and is available to download in Google Doc format from the Mapping Mountains site.

The Fours - The 400m Hills of England by Myrddyn Phillips and Aled Williams

The name the hill is listed by is Owlands Barf, and it is adjoined to the Great Shunner Fell group of hills, which are situated in the English Pennines, and it is positioned with minor roads to its north-east and south-west, and the B6270 road to its south, and has the village of Reeth towards the south south-west.

When the Introduction to the first group of hills for the updated and revised listing of the The Fours – The 400m Hills of England was published by Mapping Mountains on the 10^th September 2022, it was announced that the accompanying sub lists were being revised with the two 390m categories dispensed with and the criteria and name of the 400m Sub-Fours revised.  The one accompanying sub list is now named the Sub-Fours with its criteria being all English hills 400m and above and below 500m in height that have 15m and more and below 30m of drop.

Prior to this revision this hill was listed with 16m of drop, based on the 419m summit spot height that appeared on the Ordnance Survey Vector Map Local hosted on the Geograph website and which was entitled the Interactive Coverage Map and the 403m col spot height that appears on the Ordnance Survey 1:25,000 Explorer map. 

Extract from the Ordnance Survey 1:25,000 Explorer map

However, it was not until LIDAR became available that the details for this hill could be accurately re-assessed.  The LIDAR (Light Detection & Ranging) technique produced highly accurate height data that is now freely available for much of England and Wales. 

LIDAR summit image of Owlands Barf (NZ 049 017)

LIDAR analysis gives the height of this hill as 422.0m and when compared to its originally listed summit height this comes within the parameters of the Significant Height Revisions used within this page heading, these parameters are:

The term Significant Height Revisions applies to any listed hill whose interpolated height and Ordnance Survey, Harvey or other interactive map summit spot height has a 2m or more discrepancy when compared to the survey result produced by the Trimble GeoXH 6000 or analysis of data produced via LIDAR.  Also included are hills whose summit map data is missing an uppermost ring contour when compared with the data produced by the Trimble or by LIDAR analysis.

Therefore, the new listed summit height of this hill is 422.0m and this was derived from LIDAR analysis, this is 3.0m higher than the originally listed 419m summit height, which was based on the spot height that appeared on the Ordnance Survey Vector Map Local hosted on the Geograph website and which was entitled the Interactive Coverage Map. 

 

The full details for the hill are:

Group:  Great Shunner Fell

Name:  Owlands Barf

OS 1:50,000 map:  92

Summit Height (New Height):  422.0m (LIDAR)

Summit Grid Reference:  NZ 04914 01757 (LIDAR)

Col Height:  404.8m (LIDAR)

Col Grid Reference:  NZ 04555 01835 (LIDAR)

Drop:  17.2m (LIDAR)

 

Myrddyn Phillips and Aled Williams (August 2025) 

Mapping Mountains - Significant Height Revisions - The Fours - The 400m Hills of England

Heights Quarry (NY 923 391) - 38th significant height revision

Hill Reclassifications post for Heights Quarry

 

There has been a Significant Height Revision to a hill that is listed in the The Fours – The 400m Hills of England, with the summit height, col height and their locations, the drop and status of the hill derived from LIDAR analysis conducted by Myrddyn Phillips. 

LIDAR image of Heights Quarry (NY 923 391)

The criteria for the list that this height revision applies to are:

The Fours – The 400m Hills of England - English hills at or above 400m and below 500m in height that have 30m minimum drop, accompanying the main list is a sub list entitled the Sub-Fours, the criteria for which are all English hills at or above 400m and below 500m in height that have 15m or more and below 30m of drop.  The list is co-authored by Myrddyn Phillips and Aled Williams and is available to download in Google Doc format from the Mapping Mountains site.

The Fours - The 400m Hills of England by Myrddyn Phillips and Aled Williams

The name the hill is listed by is Heights Quarry, and it is adjoined to the Burnhope Seat group of hills, which are situated in the Pennines of northern England, and it is positioned with minor roads to its north, west and east, and the A689 road to its south, and has the town of Stanhope towards the east.

When the Introduction to the first group of hills for the updated and revised listing of the The Fours – The 400m Hills of England was published by Mapping Mountains on the 10^th September 2022, it was announced that the accompanying sub lists were being revised with the two 390m categories dispensed with and the criteria and name of the 400m Sub-Fours revised.  The one accompanying sub list is now named the Sub-Fours with its criteria being all English hills 400m and above and below 500m in height that have 15m and more and below 30m of drop. 

Extract from the Ordnance Survey 1:25,000 Explorer map

Prior to this revision this hill was not listed, with subsequent interpolation giving it an estimated c 14m of drop, based on the 427m summit spot height that appears on the DataMapWales and an estimated c 413m col height, based on interpolation of 5m contouring between 410m – 415m. 

Extract from the DataMapWales

However, it was not until LIDAR became available that the details for this hill could be accurately re-assessed.  The LIDAR (Light Detection & Ranging) technique produced highly accurate height data that is now freely available for much of England and Wales. 

LIDAR summit image of Heights Quarry (NY 923 391)

LIDAR analysis gives the height of this hill as 427.6m and when compared to details on the contemporary Ordnance Survey 1:25,000 Explorer map, this comes within the parameters of the Significant Height Revisions used within this page heading, these parameters are:

The term Significant Height Revisions applies to any listed hill whose interpolated height and Ordnance Survey, Harvey or other interactive map summit spot height has a 2m or more discrepancy when compared to the survey result produced by the Trimble GeoXH 6000 or analysis of data produced via LIDAR.  Also included are hills whose summit map data is missing an uppermost ring contour when compared with the data produced by the Trimble or by LIDAR analysis.

Therefore, the new listed summit height of this hill is 427.6m and this was derived from LIDAR analysis, this is 17.6m higher than the 410m contour that butts up against the boundary of the quarry that is relatively close to the summit of this hill on the Ordnance Survey 1:25,000 Explorer map. 

 

The full details for the hill are:

Group:  Burnhope Seat

Name:  Heigts Quarry

OS 1:50,000 map:  91, 92

Summit Height (New Height):  427.6m (LIDAR)

Summit Grid Reference:  NY 92377 39123 (LIDAR)

Col Height:  412.2m (LIDAR)

Col Grid Reference:  NY 92227 39261 (LIDAR)

Drop:  15.4m (LIDAR)

 

Myrddyn Phillips and Aled Williams (August 2025) 

Mapping Mountains - Significant Height Revisions - The Fours - The 400m Hills of England

Rowantree Knots (NY 449 052) - 37th significant height revision

Hill Reclassifications post for Rowantree Knots

 

There has been a Significant Height Revision to a hill that is listed in the The Fours – The 400m Hills of England, with the summit height, col height and their locations, the drop and status of the hill derived from LIDAR analysis conducted by Myrddyn Phillips. 

LIDAR image of Rowantree Knots (NY 449 052)

The criteria for the list that this height revision applies to are:

The Fours – The 400m Hills of England - English hills at or above 400m and below 500m in height that have 30m minimum drop, accompanying the main list is a sub list entitled the Sub-Fours, the criteria for which are all English hills at or above 400m and below 500m in height that have 15m or more and below 30m of drop.  The list is co-authored by Myrddyn Phillips and Aled Williams and is available to download in Google Doc format from the Mapping Mountains site.

The Fours - The 400m Hills of England by Myrddyn Phillips and Aled Williams

The name the hill is listed by is Rowantree Knots, and it is adjoined to the High Street group of hills, which are situated in the English Lake District, and it is positioned with the A492 road to its west and a minor road to its south-east, and has the town of Windermere towards the south-west.

When the Introduction to the first group of hills for the updated and revised listing of the The Fours – The 400m Hills of England was published by Mapping Mountains on the 10^th September 2022, it was announced that the accompanying sub lists were being revised with the two 390m categories dispensed with and the criteria and name of the 400m Sub-Fours revised.  The one accompanying sub list is now named the Sub-Fours with its criteria being all English hills 400m and above and below 500m in height that have 15m and more and below 30m of drop.

Prior to this revision this hill was not listed, with subsequent interpolation giving it an estimated c 13m of drop, based on an estimated c 422m summit height and an estimated c 409m col height, with both heights based on interpolation of 10m contouring. 

Extract from the Ordnance Survey 1:25,000 Explorer map

However, it was not until LIDAR became available that the details for this hill could be accurately re-assessed.  The LIDAR (Light Detection & Ranging) technique produced highly accurate height data that is now freely available for much of England and Wales. 

LIDAR summit image of Rowantree Knots (NY 449 052)

LIDAR analysis gives the height of this hill as 425.5m and when compared to its originally listed summit height this comes within the parameters of the Significant Height Revisions used within this page heading, these parameters are:

The term Significant Height Revisions applies to any listed hill whose interpolated height and Ordnance Survey, Harvey or other interactive map summit spot height has a 2m or more discrepancy when compared to the survey result produced by the Trimble GeoXH 6000 or analysis of data produced via LIDAR.  Also included are hills whose summit map data is missing an uppermost ring contour when compared with the data produced by the Trimble or by LIDAR analysis.

Therefore, the new listed summit height of this hill is 425.5m and this was derived from LIDAR analysis, this is 3.5m higher than the originally listed c 422m summit height, which was based on interpolation of 10m contouring that appears on the Ordnance Survey 1:25,000 Explorer map. 

 

The full details for the hill are:

Group:  High Street

Name:  Rowantree Knots

OS 1:50,000 map:  90

Summit Height (New Height):  425.5m (LIDAR)

Summit Grid Reference:  NY 44987 05234 (LIDAR)

Col Height:  408.9m (LIDAR)

Col Grid Reference:  NY 44915 05276 (LIDAR)

Drop:  16.5m (LIDAR)

 

Myrddyn Phillips and Aled Williams (June 2025)

Mapping Mountains - Significant Height Revisions - The Fours - The 400m Hills of England

High Wythow (SD 300 990) - 36th significant height revision

Hill Reclassifications post for High Wythow

 

There has been a Significant Height Revision to a hill that is listed in the The Fours – The 400m Hills of England, with the summit height, col height and their locations, the drop and status of the hill derived from LIDAR analysis conducted by Myrddyn Phillips. 

LIDAR image of High Wythow (SD 300 990)

The criteria for the list that this height revision applies to are:

The Fours – The 400m Hills of England - English hills at or above 400m and below 500m in height that have 30m minimum drop, accompanying the main list is a sub list entitled the Sub-Fours, the criteria for which are all English hills at or above 400m and below 500m in height that have 15m or more and below 30m of drop.  The list is co-authored by Myrddyn Phillips and Aled Williams and is available to download in Google Doc format from the Mapping Mountains site.

The Fours - The 400m Hills of England by Myrddyn Phillips and Aled Williams

The name the hill is listed by is High Wythow, and it is adjoined to the The Old Man of Coniston group of hills, which are situated in the English Lake District, and it has the A593 road to ts south-east and the village of Coniston towards the south.

When the Introduction to the first group of hills for the updated and revised listing of the The Fours – The 400m Hills of England was published by Mapping Mountains on the 10^th September 2022, it was announced that the accompanying sub lists were being revised with the two 390m categories dispensed with and the criteria and name of the 400m Sub-Fours revised.  The one accompanying sub list is now named the Sub-Fours with its criteria being all English hills 400m and above and below 500m in height that have 15m and more and below 30m of drop.

Prior to this revision this hill was not listed, with subsequent interpolation giving it an estimated c 10m of drop, based on an estimated c 408m summit height and an estimated c 398m col height, with both heights based on interpolation of 10m contouring. 

Extract from the Ordnance Survey 1:25,000 Explorer map

However, it was not until LIDAR became available that the details for this hill could be accurately re-assessed.  The LIDAR (Light Detection & Ranging) technique produced highly accurate height data that is now freely available for much of England and Wales. 

LIDAR summit image of High Wythow (SD 300 990)

LIDAR analysis gives the height of this hill as 410.0m positioned at SD 30033 99023, and when compared to its originally listed summit height this comes within the parameters of the Significant Height Revisions used within this page heading, these parameters are:

The term Significant Height Revisions applies to any listed hill whose interpolated height and Ordnance Survey, Harvey or other interactive map summit spot height has a 2m or more discrepancy when compared to the survey result produced by the Trimble GeoXH 6000 or analysis of data produced via LIDAR.  Also included are hills whose summit map data is missing an uppermost ring contour when compared with the data produced by the Trimble or by LIDAR analysis.

Therefore, the new listed summit height of this hill is 410.0m and this was derived from LIDAR analysis, this is 2.0m higher than the originally listed c 408m summit height, which was based on interpolation of 10m contouring that appears on the Ordnance Survey 1:25,000 Explorer map. 

 

The full details for the hill are:

Group:  The Old Man of Coniston

Name:  High Wythow

OS 1:50,000 map:  96, 97

Summit Height (New Height):  410.0m (LIDAR)

Summit Grid Reference:  SD 30033 99023 (LIDAR)

Col Height:  394.5m (LIDAR)

Col Grid Reference:  SD 29942 99029 (LIDAR)

Drop:  15.5m (LIDAR)

 

Myrddyn Phillips and Aled Williams (April 2025)