The landscaper Michel Desvigne has reconstructed 323 ft (100 m) of Roman fortifications on the exterior space of the MuséoParc Alésia. These double fortifications have an interior line called contravallation and an exterior line called circumvallation. They offer a glimpse of the 9.3 miles (15 km) of contravallations and 13 miles (21 km) of circumvallations set up by Julius Caesar and his legions to overcome the Gallic forces of Vercingétorix. The contravallations blocked the Gauls on Mont Auxois, while the circumvallations protected the Romans from an external attack by the relief army.