Fort Saint-Père, Military fort in Saint-Père-Marc-en-Poulet, France.

Fort Saint-Père is a quadrilateral fort with four corner bastions (Roy, Artois, Reine, Monsieur) linked by thick ramparts and set within a wide ditch. Its entrance was closed by a drawbridge flanked by two guardhouses. The powder magazine measures 46 by 13 metres, and 26 casemates housed 600 soldiers. A low stone wall and a stone building with a rounded brick arch and four red doors stand near the grounds.

The fortification was built between 1777 and 1785 under King Louis XVI to protect Saint-Malo's land route from British threats. Construction occurred during a period when France was strengthening its coastal defenses.

Since 1994 the fort has hosted La Route du Rock, which moved here after a test concert by Noir Désir in August 1993. The powder magazine's buttresses serve as artists' dressing rooms, the 1880 arsenal as the canteen, and the King's and Queen's bastions as offices and press space. No Logo BZH has been held here since 2017, drawing up to 42,000 festival-goers in August 2023.

The fort sits approximately 9 kilometers south of Saint-Malo and is accessible year-round. The grounds are maintained using an ecological approach with grazing goats to naturally manage vegetation.

Inside the fort lies one of Europe's largest 18th-century powder magazines, constructed with external buttresses for reinforcement. This massive structure demonstrates the careful engineering required for storing explosives safely.