Cefn yr Ystrad

Cefn yr Ystrad is a mountain in the Brecon Beacons National Park in Wales. It stands as an outlier of the Central Beacons group, rising to the east of Pontsticill Reservoir. The broad ridge runs northeast to southwest and reaches 619 metres at its highest point. The summit area is wild moorland marked by a trig point. The hill’s geology includes Carboniferous Limestone and Twrch Sandstone, with ice-smoothed rock pavements and loose stones across the slopes. The hill holds many archaeological sites from the Bronze Age to the industrial period. Notable among them are Garn Felen and Carn-y-Bugail, a 15-metre-diameter burial cairn southeast of the summit. Nineteenth-century boundary stones bearing the letters ‘D of B, TM’ and ‘GH’ mark the estates of the Duke of Beaufort and the Gwynne Holford family. Abandoned limestone quarries such as Cwar Blaen-dyffryn and Cwar yr Ystrad lie on the northern and northwestern flanks. A bridleway from Pontsticill skirts the northwestern edge of the hill, heading toward Dyffryn Crawnon and the Usk Valley. The open countryside allows unrestricted walking access. The summit offers wide views over the Brecon Beacons, while shakeholes and quarries add rugged character to the landscape.