Château de la Chasse, Medieval castle in Saint-Prix, France

Château de la Chasse stands at the edge of the Montmorency forest, its rough grey rubble walls with lighter quoins rising straight from the water. A taller central block with a plain gable and a semi-circular turret under a dark conical roof is flanked by a lower steep-roofed wing and a flat-roofed extension; a rectangular doorway opens near the waterline.

The castle was built in the 13th century under Mathieu II de Montmorency and later served as a garrison during times of conflict. It received royal visits and witnessed important shifts in French history.

The name does not come from hunting, despite the game-rich forest, but probably from the Gallic word cassanos, meaning oak. A 12th-century Latin charter spells it Chacia, resisting the Latinisation clerics usually applied. The castle was originally called Chasse Mornay.

The castle stands in the Montmorency forest, reached on foot by about 800 m along the Chemin de Montlignon au Château, a forest road starting from two car parks on either side of the D 909 between Montlignon and Bouffémont. The building is not open to visitors; it is seen from the outside, near the Route des Fonds and the Carrefour de la Fontaine.

In the 15th century, a family dispute at the castle led to a French saying about disobedience that people still know today. This story shows how local events became part of the language itself.