Rock Piles, or Cairns, Afon Mellte (Mellte River), Brecon Beacons, Wales
A cairn is a man-made pile (or stack) of stones. ... Cairns have been and are used for a broad variety of purposes, from prehistoric times to the present. In modern times, cairns are often erected as landmarks, a use they have had since ancient times.
Walking from Sgwd Clun Gwyn towards Sgwd y Pannwr we came across this bend in the river. The whole area was full of these stone cairns, even on the trees, and the beautiful colours of the stones was breathtaking.