The Citadel Henry II wanted so much, was enlarged by the Dukes of Gondi, of Retz, by Superintendent Fouquet and later by Vauban. The English occupied this citadel until 1763. It was also a prison, in particular for La Voisin, who was involved in the sinister "Poison affair", and by the Haitian Placide Toussaint-Louverture. In 1960, the army abandoned it; it now houses the Historical Museum. Do not miss the circular powder magazine, the large arsenal, and warehouses of Louis XII.