Walls of Montgròs Monument · el Brull, Osona, Barcelona Walls of Iberian date in the district of El Brull, at the foot of the Montseny, built by the Ausetani to close off the Montgròs pass and declared bien cultural de interés nacional (Catalonia's highest level of heritage protection). The defended enclosure covers about nine hectares; the wall, some 145 metres long, 5 metres wide and up to 3-4 metres high where preserved, was raised without foundations directly on the rock or on a layer of clay containing remains of an earlier Late Bronze Age settlement. Two trapezoidal towers were built at its ends, and the entrance, to the south, was defended by a small bastion. Discovered in 1974 and still under excavation, the walls are dated between the 4th and 3rd centuries BC, with Roman-period alterations, and have proved key to the study of the Iberian world and the Ausetani. Photo: Pnfodikly (CC BY-SA 3.0) What to see and do in el Brull