A Benedictine monastery.
This is one of Spain's oldest churches.
It was founded as a Benedictine monastery at the end of the 11th century. Its main entrance is Romanesque in style. Inside it has three naves and a transept with three apses. The choir stalls are Gothic. However, its most outstanding feature is unquestionably the Romanesque cloister. The church, declared a National Monument in 1886, houses the tombs of King Alfonso I "the Warrior" and King Ramiro II "the Monk".