Gilwern Hill, Powys

The hill is composed from a range of lower and middle Ordovician volcaniclastic rocks which form a part of the Builth Inlier. Palaeontologists Pete Lawrance and Brian Beveridge have spent 30 years examining fossils from a privately owned limestone quarry on the hill. Amongst fossils so far identified at this location are the trilobites Meadowtownella, Bettonolithus, Protolloydolithus and Anebolithus together with Conulariida, Iocrinus, Clonograptus and starfish^[1]

There are two prehistoric stone rows at the southern end of the hill, each with a large stone, more than 2m high, at one end.^[2]

52°12′N 3°20′W / 52.200°N 3.333°W / 52.200; -3.333