Situated on theEnglish Channel, on the D19 road, 20 miles (32 km) west ofAbbeville, in the southwest of the department, Ault possesses chalk cliffs overlooking a beach of pebbles (and sand at low tide). To the south of the town is a large wooded area, the ‘Bois de Cise’, in a valley that leads on to the coast. To the north, the cliffs descend to the level of the beach at Onival. The area around the town, the 'hâble d’Ault' was mostly tidal marshland that has been reclaimed from the sea. Cattle, sheep and game are raised here.
Ault had a station on thestandard gaugeWoincourt to Onival line, which closed to passengers in May 1939, but saw much use duringWorld War II to move materials for theAtlantic Wall. During the war, ametre gauge line was laid alongside the road fromLanchères, on theCFBS, to Ault. This line was dismantled after the war.[3]
The town has paid a heavy price defending itself against the sea, which is constantly washing away the beach, cliffs and public spaces, such as the car parks and gardens. The problem is ongoing. A "balcony on the sea", a huge concrete construction has been built but the risks remain. Signs of wear of the dyke under the casino have been noted.