Mynydd y Grug is Wales’ latest SOTA summit. Robert @M0RWX activated the summit shortly after midnight on 2nd March 2026, SOTAs 24th birthday. Due to a misunderstanding in the communication Robert found himself alone on the summit, after initial discussions of a mass activation. The local chasers had the summit activated before he managed to put out a CQ call which hopefully made him feel more welcome. A great achievement and well deserved first for Robert.
Mynydd y Grug translates to English as “Heather Mountain” and is pronounced: Myn-: sounds like “Mun” (rhymes with sun), ydd: sounds like “ith”, y sounds like “uh” (unstressed). Grug: sounds like “Greeg” (hard G, long ‘ee’, hard G).
South Wales is my home; the people are my people. I am proud of these hills, the people, and our industrial heritage.
One of the legacies of our industrial past is a fantastic rail network serving the South Wales Valleys. I took the Rhymney Valley line to Hengoed which passes Caerphilly Castle and provides views of a large section of the route.
My walk started with a rather splendid riveted, lattice section bridge, with a hot rolled section proudly bearing the name GKB Cardiff. I moved to Cardiff and started at the GKN South Wales apprentice workshops in 1984, going on to work in the 16 inch medium section mill on the site where this steel was produced.
The track bed of a disused railway line takes you from the station, over Hengoed viaduct to Maesycwmmer and the site of Maesycwmmer Junction Colliery.
From Maesycwmmer Junction Colliery the path crosses a golf course to the site of Gelli-deg Colliery.
My route took me to the site of 6 collieries, and within a few miles of many more. It is difficult to fully appreciate the extent of coal mining in South Wales. After nationalisation in 1947 there were 246 working collieries in the South Wales Coalfield. The list is quite staggering as is the map.
The South Wales coalfield was considered the most dangerous in the UK with the Welsh Mine Disasters website listing over 6,000 Welsh miners killer at their workplace. Many more died as a result of mining related illnesses.
Just across the valley is the site of Universal colliery where on 14 October 1913. The Senghenydd explosion killed 439 miners and a rescuer. The report makes sobering reading.
The Rhymney Valley Ridgeway Walk provides a good track from the golf course to the summit passing windmills, an ancient tumulus and enclosure, and a commercial woodland. It is really rather pleasant.
Mynydd y Grug summit is a spoil tip from Bedwas Navigation Colliery. There are controversial plans to rework the tips, extracting coal, and reprofile the tips. In the meantime we are able to access the summit.
The summit is rather barren, but not unpleasant. It offers a seat, plenty of space for antennas, and great views. To the East you can see the second Severn Crossing. Newport, Cardiff, Brean Down, Flat Holm and Steep Holm islands, Penarth head, and Aberthaw power station are all clearly visible as you scan along the coast. Turning to the North you can see the summits of Bannau Brycheiniog (The Brecon Beacons).
The Rhymney Valley Ridgeway Walk continues East.
A picturesque path descends through Graig Goch Nature reserve onto a track to the Sirhowy Valley Country Park, with parking on the site of Black Vein Colliery
I crossed the track and followed the Sirhowy River under the elevated roads before making my way to Cross Keys station.
Robert has posted routes to the summit from the North and the East with notes. My route followed Robert’s paths, extending them into a linear walk.
Mynydd y Grug may not be everyone’s idea of unspoiled beauty and rustic charm. I rather like our new summit and would encourage you to enjoy it while we still have access.
73, Kevin
…thanks for the summit Robert. So, 2 chases of the new one means I have to activate for a complete 
.
