Dolmen del Pasomuerto Monument · Castillonuevo/Gazteluberri, Sangüesa, Navarra Image of Castillonuevo/Gazteluberri, not of the place itself. A megalithic monument of the Leire-Illón station, with a circular tumulus of central stones with no visible chamber slabs, studied around 1952 by the archaeologist Juan Maluquer de Motes. Photo: Jialxv (CC0) What to see and do in Castillonuevo/Gazteluberri