On the floor of the Conwy Valley and overlain by a hedgebank are several upright and displaced megaliths, which represent the remains of Porth Llwyd burial chamber. The monument was damaged by the torrent of water and debris released when the Eigiau Dam (nprn 276300) burst in 1925. The site now occupied by Dolgarrog Hydro-electric Power Station (nprn 85420).
RCAHMW, 12 June 2008.