The historic Benedictine abbey was founded in 1063 by William the Conqueror. The complex includes the Doge's Palace, the Watchtower, the monastery buildings and the church, which is one of the most important and best-preserved Romanesque buildings in Normandy, although it has Gothic elements.
The palace was built in the 14th century and was most likely used to host distinguished guests. It has three storeys and is 47 m long and 12 m wide. Currently, it houses a spacious chapel and exhibition space. The Watchtower building, originally also used to host guests, dates from the same period.
In the 18th century, the complex was extended to include monastery buildings with a picturesque cloister and Tuscan-style galleries. In the 1960s, a French-style garden was also recreated here.