Bastille
The Bastille was built during the Hundred Years' War. It was called the Bastion de Saint-Antoine. At first it was just the Saint-Antoine gate, but from 1370 to 1383, this gate was made bigger and became a fortress. It defended the east end of Paris and the Hôtel Saint-Pol royal palace. After the war, it was turned into a prison. Louis XIII(13) was the first king to send prisoners there.