Monday, 19 February 2024

Mapping Mountains – Trimble Surveys – Moel y Gamelin

 

27.01.24  Caer Drewyn (SJ 091 444) 

Caer Drewyn (SJ 091 444)

The high point of Caer Drewyn is listed as a Subhump and Trichant.  This would be enough to encourage many a hill bagger to visit, but it is the remains of the Iron Age hill fort that is the main attraction.  The stone walled construction is perfectly placed overlooking two river valleys, with the Afon Dyfrdwy (River Dee) to its south and a tributary to its west.

Cofein reports that the hill fort had three phases of construction, with the initial part surviving as an earthwork to the north-east of the main construction and which is evident close to the high point of the hill, which is known locally after its main feature of the ancient hill fort; Caer Drewyn. 

Mosaic of Caer Drewyn outside the leisure centre in Corwen

The summit of this hill had previously been surveyed by John Barnard and Graham Jackson and it was this that was our objective for the day, that and a meal and catch up and a few hours spent in good company.  We met in Y Bala and wandered in to town for a hearty breakfast in Hoffi Coffi.  After an hour or so of nourishment and conversation we took two cars north-eastward to Corwen and parked on the northern side of the river in the leisure centre car park.  This would enable Mark to head directly back to Mold after the walk and for Aled to drive back to Y Bala where my car had been left, before he continued to Porthmadog and I headed home to Welshpool.

Making our way up the muddied narrow lane

From the convenience of the car park it’s not a great distance to the top of Caer Drewyn, however it is steep and especially so if opting for the direct path, which we followed.  But before the steep part we leisurely walked past the entrance to the leisure centre with me setting a comfortable slow plod at the back, before venturing a short distance up the B5437 road which was closed to traffic beyond its intersection with the bridge that crosses the river to the centre of Corwen.  Beyond the intersection we took the first left and headed up a muddied narrow lane to where a public footpath sign indicated the start of the steep uphill. 

The view south-west during the ascent of Caer Drewyn

Thankfully with a few stops to regain breath and enjoy the ever expanding view the steep bit was not too taxing.  This brought us over a green lane which we used as our descent route before continuing up to the remains of the walled enclosure.  The view extended toward Aran Fawddwy and the pyramidal coned summit profile of Arenig Fawr, and although conditions were overcast both were clear of cloud.  Sadly the sun did not give colour to the land until we arrived back at the cars, but this did not detract from the views, however just a little flash of sunlight can add so much to an overcast day and especially so at this time of year, when the land can become illuminated with the slightest direct sunlight. 

Mark and Aled making their way up the ancient embankment

As Mark and Aled followed a path on the ancient embankment, I kept to another path just below, with each joining near the top of the main walled enclosure.  The high point of the hill was just beyond with a slight descent to a gate and then a manicured green field leading to the summit of the hill. 

The field leading to the summit of Caer Drewyn

The high point of Caer Drewyn consists of a small mound with embedded rock.  I soon had the Trimble aligned with its high point and quickly measured the offset between its internal antenna and the ground at its base, and when the 0.1m accuracy level appeared on the screen I pressed Log and walked away so as not to disturb satellite reception. 

The Trimble GeoXH 6000 gathering data at the summit of Caer Drewyn

Once the equipment had done its stuff and was packed away, only the descent remained, which for me now meant I could at least talk, with much of the uphill consisting of a huff and a puff.  Reversing our inward route to the gate we then followed the green track as it gently lost height and zig zagged around the hill regaining our inward route at the muddied narrow lane.  It proved an ideal hill to visit for this time of year and two hours after setting off we were back at the awaiting cars. 

 

Survey Result:

 

Caer Drewyn (significant name change)         

Summit Height:  313.5m (converted to OSGM15, Leica GS15)

Summit Grid Reference:  SJ 09127 44416 (Leica GS15)

Bwlch Height:  222.7m (LIDAR)

Bwlch Grid Reference:  SJ 09770 45600 (LIDAR)

Drop:  90.8m (Leica GS15 summit and LIDAR bwlch) (Trichant addition)

Dominance:  28.96% (Leica GS15 summit and LIDAR bwlch)

 

 

For further details please consult the Trimble Survey Spreadsheet

 

 

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