The Château de Beynes is a is a ruined castle located in the town of Beynes, along the Mauldre River in the French département of Yvelines (Île-de-France).


The first castle, a motte-and-bailey, was built during the 11th century, in the bottom of the valley of the Mauldre River, even when castles were built on heights. It had a defensive role at that time, with the river as a western defence line of the Royal domain, defending against Normandy and other possible combatants. It was owned by the English during the Hundred Years' War.

Later, the castle lost its defensive role after the extension of the Royal territories; circa 1450, Robert d'Estouteville transformed the castle into a more comfortable residence by dismantling the keep and adapting the fortifications to the incipient artillery.

Other transformations were performed during the 15th century, particularly under Philibert de l'Orme.

In 1536, the castle was given to Diane de Poitiers by Henri II.

The castle was totally abandoned during the 18th century and fell in ruins and was used as a stone quarry for the village constructions.


The castle has an oval shape surrounded by a moat; nine towers stand along the curtain walls.

Since the transformations of the 15th century, a paved central courtyard crosses the castle. Two châtelets (east and west) defend the two entries to the castle, and a barbican also protects the west access.

Modern days

The whole remains of the castle were listed as a Monument historique in November 1959. The castle was bought by the municipality in 1967, and from 1995 to 1999 excavations and consolidation works have stopped its deterioration. Presently, an active association is restoring the castle.