Cwm Craig Ddu is a roadside section found to the east of Llangammarch Wells, along the B4519. A disused quarry (now overgrown) is also present on the hilltop, but fossils can really only now be found along the cutting. Early fossil plants and small bivalves can be collected here. This site is a SSSI, so hammering the bedrock is strictly prohibited. Silurian, Roadside Cutting, Rating: ♦♦♦