This imposing building wasn't built in a day. In the 12th Century, King Philippe-Auguste commissioned the construction of a manor house in the Bois de Vincennes. It was fortified two centuries later. Its flamboyant Gothic-style chapel wasn't finished until the 15th Century and it was King Louis XV who, in the 18th Century, added the King and Queen's pavilions. The First Empire saw the takeover by the army of the castle, which became an arsenal. There are today two museums in the dungeon and the royal pavilions. The Sainte-Chapelle has a nave and rose-windows in magnificent stone.