The Musée Ducal (Ducal Museum) covers the history of the Duchy of Bouillon and, inevitably, focuses on Godfrey of Bouillon and the First Crusade of 1096–1099. The collection includes medieval armour, documents, models of the castle at various periods, and exhibits on the history of the town under successive rulers — French, Habsburg, and Belgian.
The museum is not large and can be seen in under an hour. Combined with the castle visit it gives useful context. There are also rooms covering local folklore and traditional crafts of the Belgian Ardennes. Located in a 17th-century building in the old town centre.