The abbey founded in the 7C, then rebuilt in the 10C, was turned into a citadel called the "Spaniards' Castle". by Emperor Charles V. It was demolished in the 19C and the only abbey remains are one Gothic cloister gallery, the Romanesque lavabo, chapter-house gemeled windows and especially the 12C refectory with its fine ship's hull-shaped timber ceiling, Romanesque frescoes and a large collection of tombstones.