The planimetry of the Romanesque church

The Romanesque church that has survived to the present day was preceded by another smaller church with three naves and three semicircular apses from the 11th century, and under it the original church of smaller dimensions, with a single nave and a straight apse built in the X century, as Martínez Álava explained. The enlargement of the Romanesque temple under study began with the chevet, with triple apse in battery, begun in the second third of the 12th century, to which was added in the last third of that century the Wayside Cross and the three naves, which were completed at the end of the first third of the 13th century, advancing the works from east to west, with the foundations of the pillars and lateral walls of the rest of the church, connecting the western narthex with the chevet erected in the previous phase. Therefore, a church that was undertaken in two consecutive construction phases, as revealed by the change of sandstone in the row of ashlars that runs under the capitals of the main chapel, but responding to the initial planimetric project , as denoted by the homogeneity of the floor plan, both compositionally and proportionally in its dimensions, in which a square compositional module was used, as noted by the authors of the MonumentalCatalog of Navarre.

The church has three naves, with a transept that does not stand out in plan, a dome and a chevet with three apses, closed with an oven vault, the lateral ones semicircular, and the central one more monumental and polygonal on the exterior and semicircular on the interior, following the imprint of the chevet of the disappeared Romanesque cathedral of Pamplona, as Martínez de Aguirre mentioned. The naves of three bays, square in the case of the central nave and rectangular in the lateral ones, like the arms of the Wayside Cross, are supported by very thick supports, of cruciform nucleus, with paired half-columns in their fronts and four smaller ones in the bays, which support vaults of crossed arches of square profile , between pointed sash arches that delimit the bays. This enclosure of crossed arches was also applied to the Wayside Cross of the dome, a vaulting that collapsed in the last years of the 16th century, being replaced by the dome over the avenerated troops that has survived to the present day.

At the foot of the church there is a narthex, with a length similar to a section of the naves of the temple. The initial Romanesque project consisted of the central portico under a wide quadrangular section, flanked by two powerful cubic towers, of which the one on the north side rises in plan, reformed in the 16th century, while the one on the south side was not built as it became part of the monastic rooms, although nothing has been preserved of the medieval monastery beyond the perimeter walls and some openings.