Cambrian Mountains 50
The Cambrian Mountains 50 is an 80 km route through the heart of mid-Wales — across the remote Cambrian Mountains plateau from Machynlleth to Rhayader, through some of the emptiest upland terrain in Britain.
This route has no official waymarking. Serious navigation experience is required — do not rely on GPS alone. Carry OS 1:25,000 maps and study the line before you go.
About Cambrian Mountains 50
The Cambrian Mountains are often called "the green desert of Wales" — a vast upland plateau of sheep-grazed moorland, blanket bog and reservoir catchments with almost no habitation. The 50 route crosses this terrain in a demanding two-day journey from Machynlleth to Rhayader, passing through the Nant y Moch and Claerwen reservoirs and the high ground above the Elan Valley.
Navigation skills are essential — much of the route is pathless or on faint tracks. The solitude is exceptional.
The route
Machynlleth to Pont ar Fynach (~40 km): North section across the plateau. Nant y Moch reservoir, Devil's Bridge approaches.
Pont ar Fynach to Rhayader (~40 km): South across the Elan Valley watershed. Claerwen reservoir, the Elan Valley dams.
Getting there & logistics
Start: Machynlleth. Train on the Cambrian line from Shrewsbury and Aberystwyth.
Finish: Rhayader. Bus to Llandrindod Wells; train to Swansea and Cardiff.
Best time: June to September.
Safety
Remote terrain with no mobile signal on much of the plateau. Rescue access is very slow. A PLB is recommended. In an emergency: call 999 or 112, ask for Police then Mountain Rescue. Central Beacons MRT covers some of this area. Pre-register SMS 999.
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