The first castle, from 1051, was rebuilt by the Bishop of Liège in 1523, then destroyed by the French in 1703. Its present appearance dates from the Dutch occupation (1818-1821). The citadel was turned into a museum, with reconstructions, dioramas, miscellaneous items and a small weapons collection recalling the main events of its history and that of the town. The walls, 100m above the Meuse, offer a view of the town, the collegiate church and Meuse Valley.