Château de la Rochette, Medieval castle in Lully, France.

Château de la Rochette, also called Château du Vernay, is a ruined mid-13th-century fortress on an isolated rock encircled by the Mosses stream in Lully, near the Perrignier boundary. Its remains form a polygonal enclosure flanked by a cylindrical keep to the north and two round towers at the southern corners, with a low outer wall before the southern entrance. The surviving masonry is rough grey-brown stone: a tall broken wall with dark openings, a curtain wall overgrown with ivy, and a lower ivy-streaked wall pierced by a tall arched window.

The lords of Cervens built this fortress around the middle of the 13th century as a strategic stronghold. The property remained in their family until 1840, when their control ended.

The castle's other name, Château du Vernay, comes from the hamlet of Le Vernay where it stands. Françoise de Cervens du Vernay, dame de la Rochette, bequeathed the castle and its lordship to her husband Guillaume d'Allinges, seigneur de Coudrée, by will dated 20 February 1473. The ruins were listed as a monument historique on 11 May 1932.

The location is remote and accessible only by rural roads through surrounding countryside. Visitors should wear sturdy footwear as the ground can be uneven and muddy.

The castle's other name, Château du Vernay, comes from the hamlet of Le Vernay where it stands. Françoise de Cervens du Vernay, dame de la Rochette, bequeathed the castle and its lordship to her husband Guillaume d'Allinges, lord of Coudrée, by a will dated 20 February 1473.