The former Benedictine abbey founded in 1078 is protected by a circular wall dotted with turrets. The fortified church still retains its three Romanesque turrets. The rest of the building was reconstructed in 1715 in a relatively subdued Baroque style. The Romanesque chandelier in the form of a crown dates from 1130 and is one of the rarest in the West, with those of Aachen and Hildesheim.