Ancient chambered tomb or Cromlech in Carmarthenshire, South Wales. GWAL-Y-FILIAST aka Bwrdd Arthur. Built about 3,500 years ago it is located on a steep wooded ridge overlooking the River Taff where the river changes character from slow flowing to rapids. The large capstone pointing towards the river to the west is supported by four uprights. The tomb would once have been covered by an oval or circular mound - some kerbstones remain..