Sta. Mª de La Redonda Procathedral

Built over an ancient Romanesque temple from the 12th century, the building dates from the 16th century.

It was bestowed with the title of Collegiate Church when it merged with San Martin de Albelda Church, in 1453. The building has undergone several modifications in the sixteenth, eighteenth and nineteenth centuries. It was declared a procathedral in 1959. It has three naves and three polygonal apses. Inside there are several chapels and many tombs. On the outside, its twin towers, built by Martín de Berriatúa, are noteworthy.