A church was built here in the 12C on the site of an earlier sanctuary founded by St. Helen to house the relics of St. Victor. Its towers and west part are still standing, though damaged by the Second World War. The present Gothic cathedral was begun in 1263 and not finished until the 16C. Executed by Bartholomäus Bruyn the Elder, the handsome reredos (1530) of the high altar depicts the lives of St. Victor and St. Helen. The north aisle houses the altarpiece of the Virgin and the south aisle that of St. Anthony.