Musée de l’Annonciade is one of the oldest modern art galleries in France. This 16th-century former chapel in Place Grammont contains some dross but also cracking stuff from artists connected with Provence in general and St Tropez in particular. Look out for Matisse, Utrillo, Seurat and Dufy. You should also have a look at the pointillist works of Signac, the first artist into St Tropez in the late 19th century.
References:The Château du Lude is one of the many great châteaux of the Loire Valley in France. Le Lude is the most northerly château of the Loire Valley and one of the last important historic castles in France, still inhabited by the same family for the last 260 years. The château is testimony to four centuries of French architecture, as a stronghold transformed into an elegant house during the Renaissance and the 18th century. The monument is located in the valley of Le Loir. Its gardens have evolved throughout the centuries.