Dolmen of Serra de l'Arca Nature · Aiguafreda, Osona, Barcelona A megalithic tomb formed by four large vertical slabs and one horizontal one, built between the twenty-fifth and twentieth centuries BC, in the foothills of the Montseny. It is part of a group of seven dolmens of the serra de l'Arca, a massif located in the north-western sector of the Montseny, between the municipalities of Aiguafreda and el Brull, the whole group being dated to the Chalcolithic. The mountain range gives its name to the group, since the word “arca” formerly denoted megalithic structures. Several of these tombs are included in the Inventory of the Archaeological and Palaeontological Heritage of Catalonia, although some are preserved today in a very deteriorated state, with the slabs fallen and piled up around them. Photo: Sim6albertbeltran (CC BY-SA 3.0) What to see and do in Aiguafreda