The Episcopal Palace next to the cathedral is a grand 18th-century classical building designed by Robert de Cotte, the architect who completed Versailles' chapel. It served the bishops of Verdun until the early 20th century; since 1994 it has been the Centre Mondial de la Paix, des Libertés et des Droits de l'Homme.
The palace itself is the chief attraction — fine stone façades, a courtyard, original interior plasterwork — but the rotating exhibitions on peace, war and human rights are usually thoughtful and worth an hour. Combined ticket with the cathedral cloister.