Was back in Brecon earlier this week to have a look at Gelli Nedd Iron Age Hillfort (grid ref SN91741400 ) near Ystradfellte . The surrounding area has large sinkholes with sections of massive slabs of lime stone in between . Slabs of limestone are also prominent on the west side of the fort . The fort is a single three sided fortification built on top a rocky outcrop . The west side is protected by a cliff .
Limestone slabs inside fort .
