Surrounded by a 600-meter-diameter octagonal wall, the city is laid out in a grid of 48 plots containing housing and official buildings. In the centre is the square-shaped Place d’Armes, with a well at each corner and flanked by St-Louis Church built at the same time as the town by Vauban. A tour (45 min) of the moat or ditches illustrates the complexity of Vauban’s fortifications including watchtowers, false brays, demi-lunes and counterscarps.