Tair Carn Uchaf

Its summit sits atop a plateau-like ridge at 482 metres (1,580 ft) above sea level and is marked by one of the three huge cairns which give the mountain its name.

To the south of the main ridge lies the subsidiary peak of Drysgol which reaches a height of 393 metres (1,290 ft).

Rainwater falling on the hill's northern slopes is likely to spend part of its journey underground on account of the band of Carboniferous Limestone which sweeps across this area from east to west.

Whilst the general dip of the rock strata is to the south, there are areas which have foundered due to the presence of the soluble limestone not far beneath the surface.

The Beacons Way route from Llangadog to Abergavenny runs along the northern flanks of Tair Carn Uchaf.