Porte de Châteauroux, Historical gate in medieval district, Châteauroux, France.

The Porte de Châteauroux, whose real name is porte Saint Martin, is the only gate of the enclosure of the château Raoul, also called Tour de la Vieille Prison. It was rebuilt in the 15th century. At street level a vaulted room with a dome ceiling is pierced by firing chambers and arrow slits with sights.

Built in the 13th century, the tower was the only gate in the enclosure of Château Raoul. When the ramparts were demolished it became a prison, and it was rebuilt in the 15th century. Its facades and roofs, with the passage, were listed as monuments historiques on 11 April 1973.

The gate is also known as Porte de la Vieille Prison, after its later use as a prison once the ramparts were demolished. Its true name, Porte Saint Martin, comes from the castle chapel of Saint Martin inside the Château Raoul enclosure. A stained-glass window on the Rue de la Vieille Prison side shows the arms of Châteauroux, depicting the Porte au Guédons, the town's former main gate.

The gate stands in Châteauroux's Indre department, and its vaulted ground-floor room with firing chambers and arrow slits is at street level, so it can be seen from the public roadway. The tower is now a guesthouse, so the interior is not open as a monument; visitors see the facades and roofs, listed since 11 April 1973, from outside.

The gate's real name is Porte Saint-Martin, after the castle chapel of Saint-Martin inside the Raoul castle enclosure; locals know it as the Porte de la Vieille Prison. A stained-glass window on the Rue de la Vieille Prison side shows the arms of Châteauroux, which depict the Porte au Guédons, the town's former main gate.