Maen Madoc, a 5th or 6th century pillar stone with a Latin inscription, standing beside the Roman road, Sarl Helen, near Ystradfellte in the Brecon Beacons, Powys. The Maen Madoc or Maen Madog stone is a menhir which lies adjacent to the Roman road Sarn Helen that runs across the Brecon Beacons. It stands approximately 10 feet high. It is thought to mark a Christian burial (The stone is inscribed on one side - the Latin inscription reading DERVAC(IVS) FILIVS (H)IC IACIT - 'Of Dervacus, Son of Justus. He lies here'. Though the stone is named after a Madoc, nothing is known of the Madoc referred to. The base of stone is surrounded by deeply embedded stones and this may mark the grave itself. 咄ortean / TopFoto