Dolmen of las Arnillas Nature · Valle de Sedano, Páramos, Burgos A reconstructed megalithic tomb in the district of Moradillo de Sedano, one of the most spectacular in the comarca and the centrepiece of the group of dolmens raised on these moorlands some five thousand years ago. Photo: Ángel M. Felicísimo from Mérida, España (CC BY-SA 2.0) What to see and do in Valle de Sedano