The high, flat-topped sandstone mountains at the heart of Bannau Brycheiniog, with Pen y Fan the highest peak in south Wales
Open accessNational Trust land — free to wander
Most walkers who come to Bannau Brycheiniog are heading for this central range, and the National Trust owns a large slice of it. The mountains are Old Red Sandstone, worn into long flat tops and steep north-facing scarps rather than jagged peaks. Pen y Fan is the high point at 886 metres, the highest hill in south Wales, with Corn Du beside it and Cribyn along the same ridge. The usual routes start from the Storey Arms on the A470 or from the reservoir to the south, and the popular path up Pen y Fan gets busy in summer. In a hollow below the summits, the glacial lake Llyn Cwm Llwch (cwm is Welsh for a steep-sided valley) makes a quieter target. Weather on the tops turns quickly, so take a map and check the forecast.
