Together with the Sever-valley sites around the nearby towns of Castelo de Vide and Valencia de Alcântara (in Spain), these form one of the densest clusters of megalithic sites in Europe. Among the 200+ neolithic, Bronze and Iron Age monuments within a 25 km (16 mi) range of Marvão is the 7.15m high menhir at Povoa e Meada (the largest on the Iberian peninsula), oriented to be visible from the northernmost promontory of Marvão's rock (possibly based on an alignment with the lunar calendar).