Consecrated in 1057, numerous 11C Romanesque elements, such as the sober east end surmounted by a turret, a square tower, three apses and the inner chancel, are still visible in the church. However the finest architectural element is the crypt, built to support the church above. Its structure is massive and its lines pure, with capitals of unusually short shafts. The West Portal is 12C. A wooden chest contains the remains of the first kings of Navarra.