Situated on the river Var the town of Entrevaux once stood on the border between France and Savoy. It lies on the north bank of the river, on the road that follows the valley and used to cross the frontier. First fortified as far back as Roman times, Entrevaux was surrounded by walls in medieval times and a castle was built on a pinnacle that rises high above the town on the north side.
The Spanish briefly occupied Entrevaux in the 1530s and the area saw some unrest during the French Wars of Religion in the second half of the 16th century. However none of this was enough to provoke any investment in serious artillery fortifications, so the town was essentially still a medieval fortress for most of the 17th century.
The French alpine frontier was at peace for most of the century and the need to build or maintain expensive fortifications in the region was not seen to be important. This changed in 1690 when the Savoyards made a surprise attack across the frontier, raiding Seyne-les-Alpes. Suddenly made aware of their weakness, the authorities on the French side of the border undertook rapid work to strengthen their fortresses.
The engineer assigned to the region, Niquet, hastily put together plans to enlarge some of the medieval towers to create "tower bastions", as at nearby Colmars. He also built a small hornwork next to the cathedral on the east side of town, where the Porte d'Italie gate was situated. This was the only area of the fortifications that was not protected by the river or by steep ground.
In 1692 the Savoyards made another raid across the Alps and the king sent his celebrated engineer Vauban to undertake an emergency review of the Alpine fortresses. After making plans and recommendations for the larger fortresses such as Briancon and Mont-Dauphin, Vauban finally gave his attention to Entrevaux in 1693. He designed two large tower bastions on the south side of the town, replacing one of the medieval towers modified by Niquet a few years earlier. In the Alps Vauban planned tower bastions for Gap, Digne, Colmars and Entrevaux, but only those at Entrevaux were ever built.
The main entrance to Entrevaux is via a bridge across the river. The gate is flanked by two semi-circular medieval towers. Vauban and Niquet left these towers in place, but an angled bastion was built around the foot of the south tower, which could flank the southern walls of the town, along with the tower bastions to the east. On the far side of the bridge Vauban planned a large, wide hornwork, which was rejected on the grounds of cost. Instead a small medieval-looking gatehouse was built at the south end of the bridge in the early 18th century with musket loopholes, but no provision for guns.
The medieval castle (now known as a citadel) high above the town did not escape Vauban's attention. The citadel was too inaccessible to be assaulted with heavy artillery and the ground was too steep for a bastioned trace. As a result, the citadel has no conventional bastioned fortifications, but it was given embrasures for guns and loopholes for musket defence, especially on the north side.
The citadel's defences also saw some 19th century modifications, which included changes to the north gate. The north side of the citadel was protected by a ditch carved out of the rock, which has a counterscarp gallery. This is a covered passageway that runs along the outer edge of the ditch and allowed the garrison to fire into and along the ditch.
On the south side of the citadel there was no risk of attack because the slope up from the town is extremely steep and rocky. However the citadel is very high above the town and some distance to the north, so Vauban was sceptical about its usefulness during an attack on the town. Part of the town, in particular the vulnerable Porte d'Italie, is actually obscured by the shape of the slope. To address this, Vauban planned a front of two bastions to be built part way up the slope between the town and the citadel.
Once again the requirement to keep costs down resulted in these plans being shelved. Instead two small redoubts were built on the slope to cover the east and west approaches to the town. These redoubts mounted several guns each and were much more effective for observing and covering the ground close to the town, especially the flat land to the east in front of the Porte d'Italie.
The improvements put in place by Vauban and Niquet were soon put to the test. In 1704 a Savoyard force laid siege to Entrevaux. Despite the fact that a garrison had not yet been put in place the inhabitants of the town managed to hold out for 48 days until the Savoyards withdrew. During the 18th century Vauban's recommendation for a covered way linking the town and the citadel was carried out. This covered way winds up the steep slope with 7 hairpin bends. The south side of the path is protected by a loopholed wall and there are a series of traverses to guard against ricochet fire. The two redoubts on the lower part of the slope were accessed from this covered way.
The fortifications of Entrevaux are very well preserved. The town's walls remain more or less as Vauban and Niquet left them and they can be visited from the tourist information for a small fee (on the left at the main gate). However only a small portion of the top of the walls is accessable from here and the walls can be appreciated just as easily from the outside.
The citadel can also be visited (for this it is necessary to buy a token from the tourist office - €5 in 2004 - which will operate the turnstyle at the foot of the covered way). It is quite a climb, but well worth it once you are there. I found (in summer 2004) that the citadel was undergoing restoration, but was still visitable. There are plenty of underground passages to explore (steep ladders and dangerous drops, too) so remember to take a torch.
Entrevaux has a station close to the old town and is also accessable by road, but no non-resident cars are allowed in the old town. Although in the alps it is within striking distance of the Côte-d'Azur, being fairly close to Nice and Cannes.