Myrddyn Phillips - Mapping Mountains: Mapping Mountains – Trimble Surveys

25.02.23 Moel Siabod (SH705 546, only bwlch surveyed) and Cefn y Cerrig (SH 674 545)

Having scrutinised several OS maps a circular walk was devised from the viewing-point car park (SH 658 541) between Llyn Gwynant and Pen y Gwryd. I had never started a hill walk from this point and found the idea rather novel. I arrived just after 8am and soon set off along the road to Pen y Gwryd, flanked by a stunning view of Yr Wyddfa. Remnants of recent snowfall speckled the upper slopes and the buffeting of a cold north-easterly reminded me that winter was not yet over.

Yr Wyddfa looking resplendent as ever (Photo: Aled Williams)

As I approached Pen y Gwryd, the masses bound for Yr Wyddfa were already filling up the available roadside car parking spaces. I slipped by unnoticed as I headed to the first of my surveying objectives; the critical bwlch of Moel Siabod. I had assisted Myrddyn Phillips with the survey of this pass back in 2017 and was eager to collect a couple of extra data sets given that the drop result was so close to the 600m prominence threshold for Major status (hills that appear in Mark Trengove’s list The Major Mountains of Britain and Ireland). Two data sets were taken at the bwlch, each involving a lonely five-minute vigil in the numbing chill of the north wind.

Gathering data at the bwlch of Moel Siabod (Photo: Aled Williams)

The view toward Cefn y Cerrig (Photo: Aled Williams)

Having packed away the Trimble, I headed towards the high point of the day; the potential new Welsh Highlands Sub of Cefn y Cerrig. It felt good to be out on the open mountain, although the underfoot conditions made the traverse of the moor a squelchy affair. Drier conditions prevailed once on the arm of Cefn y Cerrig was reached and a leisurely walk soon brought me to the base of the summit tor.

The view of Dyffryn Mymbyr (Photo: Aled Williams)

Gathering data at the summit of Cefn y Cerrig (Photo: Aled Williams)

I had visited the summit of Cefn y Cerrig once before in December 2005 and my memory of it as a fine rocky top was affirmed by the stunning view of Dyffryn Mymbyr. This time, there was work to do. The high point was duly located and the Trimble was placed into position for measurement. During data collection I sheltered in comfort on the south-western side of the summit rocks and spied my descent route.

Gathering data at the bwlch of Cefn y Cerrig with Yr Wyddfa as backdrop (Photo: Aled Williams)

Cefn y Cerrig (Photo: Aled Williams)

Once the Trimble had completed its task, I scrambled down the rocky facade of Cefn y Cerrig to the bwlch connecting it to its parent peak; Clogwyn Bwlch y Maen. The critical position was located beside a partially frozen pool and the final data set of the day was gathered shortly afterwards. The ground between Cefn y Cerrig and the car was pathless and wet, but quick progress was made regardless. The sudden appearance of Llyn Gwynant signalled my imminent arrival back at the car and the end of an enjoyable morning on the hill.