Mapping Mountains – Trimble Surveys – Mynydd Bach

13.05.16  Foel y Mwnt (SN 193 520)

Foel y Mwnt (SN 193 520)

The land around Mwnt entices one in with quiet lanes seemingly disappearing into themselves and a gentle way of life.  Nothing ever moves in Mwnt, except for an occasional local and holidaymaker, with life slow paced on all but a rare occasion.

Mwnt is only a small community that was once an ancient Parish and my reason for visiting it was because of its hill, which is named Foel y Mwnt.  This hill is steep sided and placed next to the sea as it laps inland against its northern coast.  It overlooks Mwnt beach which nestles in its secluded cove, beautiful in appearance it portrays welcome and sun drenched days when laziness and quietness are sought.  The beach is serenely positioned and was included in a 2011 Daily Mail article as the top of its list of Europe’s top ten loveliest hidden beaches.  Although not knowing what the other nine beaches were, I would not argue with their listing as it is rather wonderfully situated.

Mwnt beach - beautifully situated

When I arrived at the car park the sun shone down upon a land becalmed in its warmth.  The ascent of Foel y Mwnt is a relatively easy affair with three paths heading towards its slopes; I chose the central one which directed itself straight for the summit. 

As I crossed the bwlch I stopped and looked at Eglwys y Grog (Church of the Holy Cross) which is probably a 14^th century construction and which is now white washed.  This Church is like the beach, and to an extent also like the hill, as it nestles in its spot, looking unobtrusive and in keeping with the position it finds itself in.  I thought it looked rather Irish, probably more so Celtic.  Inside it was peaceful and old, with a welcoming touch.

Eglwys y Grog (Church of the Holy Cross)

As I headed toward the central path a single figure stood close to the summit and proceeded to slowly walk eastward, and sat looking out with binoculars in hand to the land below.  By the time I reached the top I was sweating and it took me a minute or so to reclaim my breath before saying hello.  We introduced ourselves and commented on how wonderful the hill was; Rodney Gotto said that he’d visited it on a number of occasions, and as I set the Trimble up we talked about the equipment and its function and this led us onto hill surveying.  During the time that the Trimble gathered its all-important five minutes of summit data we chatted about the distance that we had travelled to get to where we now were, and Rodney said that he had come from Welshpool, I had a sudden double take and asked him; ‘from where?’ ‘I live in Welshpool’, came the reply, well I had to giggle and soon we were talking about local people that we both knew and where we both lived.

Rodney Gotto - a resident of Welshpool

Gathering data at the summit of Foel y Mwnt

Picking the Trimble up from its position aligned to the highest part of the hill I looked westward down the coast beyond the glistening sea toward Ynys Aberteifi (Cardigan Island) and thought back to my visit from September of last year, which had proved another marvellous island experience, with it being late in the day as the sun sank ever deeper and illuminated colour bounced across the land.

Ynys Aberteifi (Cardigan Island)

After I packed the Trimble away we walked down the hill together taking the path that curves around its eastern side as our preferred descent route.  We said our goodbye’s at the bwlch and Rodney sauntered back to his car whilst I assessed the lay of land and took a further two data sets from the area of the bwlch.

Gathering data at the bwlch of Foel y Mwnt

The Trimble set-up position at the bwlch of Foel y Mwnt

Afterward I visited the Church and then made my way back to my car to change and check the map for my onward route to the west of St David’s for my night time sleeping spot.  As I arrived at St Justinian’s the sun ebbed downward and blazed golden across the sky, a fitting end to a wonderful day.

The end of the day

Survey Result:

Foel y Mwnt

Summit Height:  77.0m (converted to OSGM15, Trimble GeoXH 6000)

Summit Grid Reference:  SN 19347 52072 (Trimble GeoXH 6000)

Bwlch Height:  33.6m (LIDAR)

Bwlch Grid Reference:  SN 19509 51931 (LIDAR)

Drop:  43.4m (Trimble GeoXH 6000 summit and LIDAR bwlch)

Dominance:  56.41% (Trimble GeoXH 6000 summit and LIDAR bwlch)

For further details please consult the Trimble Survey Spreadsheet.

Mapping Mountains – Summit Relocations – 100m Twmpau

Pt. 173.8m (SN 225 503)

There has been a Summit Relocation to the 100m Twmpau (thirty welsh metre prominences and upward) list initiated by a survey with the Trimble GeoXH 6000, with the survey that resulted in this summit relocation being conducted on the 13^th May 2016.

The hill is adjoined to the Rhos Ymryson range of hills and is situated to the north-east of Aberteifi (Cardigan) and to the west south-west of Aberporth, with the high point of the hill being close to the small community of Felinwynt which only comprises a few houses, and as the hill does not possess a name of its own on current Ordnance Survey maps, and as I do not know an appropriate name for it either from local enquiry or from historical research it is being listed under the point (Pt. 173.8m) notation.

Access to the hill is relatively easy as it comprises a large grassy field which has a minor lane running over it in a north to south direction.  However, the high point as surveyed with the Trimble GeoXH 6000 is not on open access land and therefore permission to visit should be sought.

The highest spot height adjoined to this hill on Ordnance Survey maps is 174m and this is positioned on the minor lane and adjacent to where a fence heads westward across a field.  A data set was taken with the Trimble from the high point of the road as well as from what was deemed to be the high point of the adjacent field, the results appear below:

High point of road:  173.7m (173.695m, converted to OSGM15)

High point of field:  173.8m (173.811m, converted to OSGM15)

These two results are very close and there is a possibility that higher ground exists in the field when compared to where the Trimble set-up position was placed.  However, for now this Trimble data is the most accurate that is known for this hill, and although the corner of the field is very close to the high point of the road it is worth itemising this positional change as a summit relocation as many people may just dip their toe on the tarmac instead of visiting the land within the adjacent field.

Therefore, the known higher part of the hill as surveyed with the Trimble GeoXH 6000  is not on the minor lane as ground in the adjacent westerly field is approximately 0.12m higher.

The full details for the hill are:

Cardinal Hill:  Rhos Ymryson

Summit Height:  173.8m (converted to OSGM15)

Name:  Pt. 173.8m

OS 1:50,000 map:  145

Summit Grid Reference (New Position):  SN 22587 50306 

  

Drop:  c 55m

The Trimble GeoXH 6000 gathering data at the summit of Pt. 173.8m, with the minor road where the 174m spot height appears on the ground on the other side of the gorse hedgerow in the background of this photograph

For details on the survey that relocated the summit of this hill.

Myrddyn Phillips (May 2016)

Mapping Mountains – Trimble Surveys – Hafod Ithel

13.05.16  Pt. 173.8m (SN 225 503)

Pt. 173.8m (SN 225 503)

The ethics of roadside bagging may be thought of as dubious, but their convenience and novelty are not to be underplayed as a summit visited is just that, and if that summit just happens to be positioned on a road the ethics of what constitutes a valid ascent are easily dispensed with in favour of another tick in another list.

Today’s roadside grab was a hill that is positioned on the outskirts of Felinwynt, which is a small gathering of houses to the north-east of Aberteifi (Cardigan).  The hill constitutes a large grassed field with a minor road passing over it in a north to south direction.  The upper part of the road has a 174m spot height adjoined to it on Ordnance Survey maps, this is beside a fence in the field, with a 173m spot height given to a patch of land to the south.

I’d been out for 6½ hours earlier in the day around part of the Pumlumon range of hills before driving further south, and wanted a couple of easy P30s to visit before heading to the west of St David’s for tomorrow’s island adventure which Adrian Rayner had organised, and this roadside bag was on the way to Foel y Mwnt, which proved to be my last hill of the day.

It wasn’t difficult to find the high point of the minor road and I parked close to the grass verge, this is as the map indicates as it is opposite where the fence stretches across the greened field to the west.

Gathering data on top of an improvised tripod (my car) at the point where the 174m spot height appears on the ground

The car roof proved to be ideal as an improvised tripod and within a few minutes the Trimble was collecting data positioned 1.42m above the high point of the road.  After packing the Trimble away and as all was quiet hereabouts I decided to investigate the adjacent westerly field.  It took a little clambering to get over the fence but once in the field I marched across it following the fence line and looked back toward the hedgerow and minor road.  The highest part of land was either the hedge or the embankment where the fence was positioned; as both were judged to be man-made constructions I dismissed them as being potential points to survey.  However, as I was now in the field I thought it wise to gather another five minute data set from what looked to be its high point; this at least could be compared to that of the road.

Gathering data in the westerly field

Gathering data in the westerly field with the man-made embankment clearly higher in the background

As the Trimble gathered its customary five minutes of data I sat below and next to the fence, soaking up the afternoon’s sunshine.  Twenty three minutes after arriving I was back at the car having surveyed two potential highest points and having ticked off another P30, next stop the beautiful Foel y Mwnt.

  

Survey Result:

Pt. 173.8m

Summit Height:  173.8m (converted to OSGM15)

Summit Grid Reference:  SN 22587 50306 (summit relocation confirmed)

Drop:  c 55m

Dominance:  31.64%

For further details please consult the Trimble Survey Spreadsheet.

Mapping Mountains – Hill Reclassifications – Y Pellennig – The Remotest Hills of Wales

Bryn Llwyd (SN 835 920) - Pellennig addition  

There has been a new hill that has entered the list of Y Pellennig – The Remotest Hills of Wales, due to a recent Trimble survey.  The hill is situated in the Pumlumon group of hills in the northern part of mid Wales and is situated between the towns of Llanidloes to its south-east and Machynlleth to its north-west.

The hill was surveyed over two days on 5^th and 13^th May 2016, both in beautiful sunshine and its name is Bryn Llwyd.  It can be accessed from the east via a track that leaves a minor road toward the farm of Nant-yr-hafod, or alternatively it can be accessed from its north via a track that leaves a minor road leading toward the lake of Glaslyn, or from a track that leaves the same minor road and makes its way around the southern flank of Y Grug.  These approaches from the north have to contend with Cors yr Ebolion, which as its Welsh name suggests is a bog.  If tempted by one of these northern approaches it is advisable to keep to a path that contours the eastern flank of Banc Bugeilyn before losing height to cross the reed infested stream close to the south-west corner of the conifer plantation to the north of this hill’s summit.

Bryn Llwyd was surveyed by the Trimble GeoXH 6000 as being 501.4m (converted to OSGM15, and average of four summit surveys) high, and prior to this survey the highest point listed hereabouts was Bryn yr Ŵyn which had been regarded as being higher than Bryn Llwyd and therefore listed as the summit in the 500m Twmpau list.  However, Bryn yr Ŵyn was surveyed by the Trimble as being 499.9m (converted to OSGM15, and average of five summit surveys) high, and as contour interpolation and a rudimentary survey suggested that the connecting bwlch between these two hills was not low enough to give each sufficient drop to be listed as separate summits; only Bryn yr Ŵyn was previously listed.  This Trimble survey confirms Bryn Llwyd to be the higher summit (see Summit Relocation post) and as the nearest paved public road at SN 84696 94288 is 2.525km from the summit this hill qualifies for the listing of Y Pellennig – The Remotest Hills of Wales, having the required 15m minimum drop and 2.5km minimum distance between the summit and the nearest paved public road.

This now brings the overall total for Y Pellennig to 168 hills for the Complete list (All Wales), with the total for the Mainland Wales list being 124 hills.  The Master List will be duly updated on the Mapping Mountains site.

The full details for the hill are:

Cardinal Hill:  Pumlumon Fawr

Summit Height:  501.4m (converted to OSGM15, and average of four summit surveys)

Name:  Bryn Llwyd

OS 1:50,000 map:  135, 136

Summit Grid Reference:  SN 83574 92022

Drop:  30.3m (converted to OSGM15)

Distance:  2.525km

The list of additions and deletions in the Pellennig list since the 1^st edition of Y Pellennig – The Remotest Hills ills of wales of Wales was published by Europeaklist is as follows:

ADDITIONS

Pen Diban (SH 112 205)

Ynys Arw (SH 266 945)

Bryn Llwyd (SN 835 920) 1st survey, 2nd survey

DELETIONS

Graig Fach (SN 821 931)

Bryn Llwyd (SN 835 920) now confirmed as a Pellennig hill

ills of wales For details on the 1st Trimble survey and the 2nd Trimble survey that promoted this hill to Pellennig status.

Myrddyn Phillips and Aled Williams (May 2016)

Mapping Mountains – Summit Relocations – Y Pellennig, Yr Uchafion and 500m Twmpau

Bryn Llwyd (SN 835 920)  

There has been a Summit Relocation initiated by a survey with the Trimble GeoXH 6000 to the listings of Y Pellennig, Yr Uchafion and 500m Twmpau, with the survey that resulted in this summit relocation being conducted on the 5^th and 13^th May 2016.

The three lists that this summit relocation affects are:

Y Pellennig - The Remotest Hills of Wales, with the criteria being all hills in Wales whose summit is 2.5km or more from the nearest paved public road that have a minimum 15m of drop.  This list is co-authored by Myrddyn Phillips and Aled Williams.

Yr Uchafion, this is the working title for a list that takes in all hills in Wales at and above 500m in height that have a minimum 15m of drop.  This list is co-authored by Myrddyn Phillips and Aled Williams.

500m Twmpau (thirty welsh metre prominences and upward), with the criteria being all Welsh hills at or above 500m and below 600m in height that have a minimum 30m of drop.  This list is authored by Myrddyn Phillips.

As the hill only entered the ranks of Pellennig hills due to this survey this listing of hills is being included within this Summit Relocations heading. 

The survey was conducted in the Pumlumon range of hills over two beautiful sunny days, with the hill situated mid-way between the towns of Machynlleth to its north-west and Llanidloes to its south-east.  

The name of the hill where the summit has been re-located to is Bryn Llwyd (SN 835 920) and the name of the hill where the summit has been re-located from is Bryn yr Ŵyn (SN 839 925).  Both summits and respective bylchau were surveyed with the Trimble with their summits being connected by a bwlch that is only 9.9m below the summit height of Bryn yr Ŵyn and 11.4m below the summit height of Bryn Llwyd.

The summits of both hills possess a small uppermost 500m ring contour on Ordnance Survey maps with no adjoined spot height, with the uppermost ring contour for Bryn Llwyd being the larger.

The critical bwlch for the higher of these hills in positioned to the south-west and to my knowledge their drop has only been surveyed on three occasions, once using a basic levelling survey (BLS) method, and the other two using the Trimble GeoXH 6000.  The results from each survey appear below:

Bryn Llwyd:  summit to critical bwlch, 102.5ft (31.2m) drop (BLS), 30.3m drop (Trimble).

Bryn yr Ŵyn:  summit to connecting bwlch with Bryn Llwyd, 42.5ft (13.0m) drop (BLS), 9.9m drop (Trimble).   

I conducted the basic levelling survey in July 2000 and sent the details to Michael Dewey.  Michael assessed the information and decided to include Bryn yr Ŵyn in his list to The 500-Metre Tops of England and Wales.  The margin of uncertainly associated with the BLS method is within the error tolerance of the result, and I have wanted to re-visit and survey both hills and produce accurate absolute heights for each, ever since.  Their heights as surveyed by the Trimble GeoXH 6000 appear below:

Bryn Llwyd 501.4m (converted to OSGM15) summit at SN 83574 92022 (average of four surveys conducted over two days)

Bryn yr Ŵyn 499.9m (converted to OSGM15) summit at SN 83919 92571 (average of five surveys conducted over two days)

Therefore the position of the relocated summit is at SN 83574 92022 and it consists of grass atop an ancient mound.  The summit area and the hill itself has relatively easy underfoot conditions and consists of moor grass with a path leading from the critical bwlch to the south-west toward the connecting bwlch with Bryn yr Ŵyn.  

This re-located summit position is not given a spot height on current Ordnance Survey maps and it is approximately 660 metres south south-westward from the previously listed summit position.

The full details for the hill are:

Cardinal Hill:  Pumlumon Fawr

Summit Height:  501.4m (converted to OSGM15, and average of four summit surveys)

Name:  Bryn Llwyd

OS 1:50,000 map:  135, 136

Summit Grid Reference (New Position):  SN 83574 92022 

  

Drop:  30.3m (converted to OSGM15)

The Trimble GeoXH 6000 gathering data at the summit of Bryn Llwyd, with the summit of Bryn yr Ŵyn on the right and in the background of this photograph

For details on the 1^st Trimble survey and the 2nd Trimble survey that relocated the summit of this hill.

Myrddyn Phillips and Aled Williams (May 2016)

Mapping Mountains – Hill Reclassifications – Yr Uchafion

Graig Fach (SN 821 931) - Uchaf reclassified to 500m Sub-Uchaf

There has been a reclassification of an Uchaf to a 500m Sub-Uchaf due to a survey conducted with the Trimble GeoXH 6000.  Yr Uchafion is the draft title for a list of the Welsh 500m P15s that takes in all hills in Wales at or above 500m that have a minimum of 15m of drop, the list is a joint compilation with Aled Williams.  Details relating to this list were published on the Mapping Mountains site in November 2015.

The hill is situated in the Pumlumon group of hills in the heartland of northern mid Wales and is positioned to the south of Foel Fadian, which is the hill’s Cardinal Hill, and between the towns of Llanidloes to its south-east and Machynlleth to its north-west.  It can be easily accessed from a minor road to its north from where a track leads toward the lake of Glaslyn; the hill is positioned just to the west of this track.  Alternatively an extended route can be devised from its south where a path can be followed above the course of the Afon Hengwm.

The name of the hill is Graig Fach (the) little rock and was surveyed over two days; on 5^th May 2016 and 22nd February 2019, both in beautiful early morning sunshine.  Graig Fach has a 514m summit spot height and bwlch contouring between 490m – 500m with a 499m spot height appearing on the Ordnance Survey enlarged mapping on the Geograph website, this latter spot height is positioned on the track and interpolation suggests that it is not positioned where the critical bwlch is situated.

The bwlch consists of moor grass and heather and two data sets were taken on both days,  whilst the summit consists of a small rock and grassy knoll with five data sets taken in all from the area of the summit, resulting in the hill only having 14.7m of drop and therefore below the 15m minimum drop value required to qualify for this list.

This now revises the total of Uchaf hills which will be updated accordingly and the hill is now listed as a 500m Sub-Uchaf.

The full details for the hill are:

Cardinal Hill:  Foel Fadian

Summit Height:  513.5m (converted to OSGM15)

Name:  Graig Fach

OS 1:50,000 map:  135, 136

Summit Grid Reference:  SN 82117 93069

Drop:  14.7m (converted to OSGM15)

The reclassifications to Yr Uchafion / The Welsh 500m P15s reported on Mapping Mountains are ills of wales as follows:

RECLASSIFIED FROM UCHAF TO SUB-UCHAF

Pt. 649.8m (SH 660 452) Uchaf reclassified to 500m Sub-Uchaf with 14.8m of drop.

Graig Fach (SN 821 931) Uchaf reclassified to 500m Sub-Uchaf with 14.5m of drop.

Graig Fach (SN 821 930) now reclassified from an Uchaf to a 500m Sub-Uchaf

For details on the survey that reclassified this hill from Uchaf to 500m Sub-Uchaf status.

Myrddyn Phillips and Aled Williams (May 2016)

Mapping Mountains – Hill Reclassifications – Y Pellennig – The Remotest Hills of Wales

Graig Fach (SN 821 930) - Pellennig deletion

There has been a deletion of a hill from the list of Y Pellennig – The Remotest Hills of Wales, due to a survey with the Trimble GeoXH 6000.  The hill is situated in the Pumlumon group in northern mid Wales and is situated between the towns of Machynlleth to its north-west and Llanidloes to its south-east with the mountain lakes of Glaslyn to its north and Bugeilyn to its south.

The name of the hill is Graig Fach and it was surveyed over two days; 5^th May 2016 and 22nd February 2019, both in beautiful early morning sunshine.  The hill can be easily accessed from the north via the track that leaves a minor road toward the lake of Glaslyn, or alternatively a longer approach to the hill is from the south-west following the path above the course of the Afon Hengwm. 

Graig Fach has a 514m summit spot height and bwlch contouring between 490m – 500m with a 499m spot height appearing on the Ordnance Survey enlarged mapping on the Geograph website, this latter spot height is positioned on the track and interpolation suggests that it is not positioned where the critical bwlch is situated.

The bwlch consists of moor grass and heather and two data sets were taken on both days,  whilst the summit consists of a small rock and grassy knoll with five data sets taken in all from the area of the summit, resulting in the hill only having 14.7m of drop and therefore below the 15m minimum drop value required to qualify for this list.  This hill is a loss to the Pellennig listing as it is one that must be seldom visited and affords good views across to the expanse of wilderness situated around Llechwedd Crin and Banc Bugeilyn.

This now brings the overall total for Y Pellennig to 167 hills for the Complete list (All Wales), with the total for the Mainland Wales list also decreasing by one to 123 hills.  The Master List will be duly updated on the Mapping Mountains site.

The full details for the hill are:

Cardinal Hill:  Foel Fadian

Summit Height:  513.5m (converted to OSGM15)

Name:  Graig Fach

OS 1:50,000 map:  135, 136

Summit Grid Reference:  SN 82117 93069

Drop:  14.7m (converted to OSGM15)

The list of additions and deletions in the Pellennig list since the 1^st edition of Y Pellennig – The Remotest Hills ills of wales of Wales was published by Europeaklist is as follows:

ADDITIONS

Pen Diban (SH 112 205)

Ynys Arw (SH 266 945)

DELETIONS

Graig Fach (SN 821 930)

Graig Fach (SN 821 930) now deleted from the Y Pellennig list

For details on the survey that deleted this hill from Pellennig status.

Myrddyn Phillips and Aled Williams (May 2016)