The Château du duc d'Épernon is a castle located in Fontenay-Trésigny, in the Brie region, 43 km (27 mi) southeast of Paris. The castle is located on the Bréon creek, in front of the Saint-Martin church in the heart of the once walled old town. The history of the town is closely linked to the history of the castle. The castellans were lords of Fontenay en Brie during the Old Regime. The castle has been classified as Monument historique since October 7, 1963. The park is recorded in the pre-inventory of remarkable gardens.