Allt yr Esgair

Allt yr Esgair is a hill in the Brecon Beacons National Park in the county of Powys, south Wales. It is commonly referred to locally as simply 'The Allt'. The Welsh name signifies 'wooded slope of the ridge'. It takes the form of a northwest-southeast aligned ridge which rises to a height of 393m (1289 feet) and which overlooks the valley of the River Usk to the west and south. To the northeast are panoramic views across Llangorse Lake to the Black Mountains There is a viewfinder on the summit erected as a monument to Eirene Lloyd White, Baroness White of Rhymney. ]. It is a Marilyn with a prominence of 205 metres (672 feet).
Geology
The hill is formed from sandstones and mudstones of the Senni Beds Formation of the Old Red Sandstone laid down during the Devonian period. The lower slopes are formed from mudstones and sandstones of the slightly older St. Maughans Formation. A number of small sandstone quarries, now disused, adorn the slopes. The hill probably...