Senni, Breconshire, Powys.
Wales
National grid reference: SN 924191
Sited in a slight depression close to the source of the Afon Llia is this magnificent 11ft high trapezoid sandstone. There are faint signs of inscriptions on the western face
ROVEVI S...SOVI in Latin and VASSO in Ogam script but this is uncertain. It stands by the Sarn Helen Roman road which runs south from Brecon down the Afon Nedd valley and past the Maen Madoc. Legends say that Maen Llia loves fresh water and drinks from Afon Nedd when it hears a cock crowing.