Dolmen of Santo Tomé Nature · O Valadouro, Mariña Central, Lugo Image of O Valadouro, not of the place itself. Also called Arca do Padorno, it preserves the capstone over four orthostats and a chamber 2.30 by 1 metre, with a passage facing east; it is attributed to the farming and herding communities of the Neolithic. Photo: Estevoaei (CC BY-SA 4.0) What to see and do in O Valadouro