The cliffs are composed of Upper Cretaceous chalk deposited approximately 80 to 90 million years ago.
Coastal recession rates at Ault have historically measured up to 30 centimeters per year in certain sectors.
The Hable d'Ault, a nature reserve adjacent to the cliffs, is a former bay that was naturally sealed off from the sea by pebble ridges.
The flint found within the chalk walls was historically used as a primary building material for local 'checkerboard' masonry in Ault.
The site acts as a key observation point for migratory birds moving along the Somme coastline.
The Falaises d'Ault form the northernmost point of the Alabaster Coast, marking the geological transition where the chalk cliffs of Normandy meet the sandy plains of the Somme. These cliffs are subject to active coastal erosion, resulting in a retreating shoreline that has historically threatened local architecture. The site offers an expansive vantage point over the English Channel and the pebble-strewn beach below. A marked coastal path provides a direct walking route connecting the town of Ault to the neighboring resort of Mers-les-Bains. The landscape is characterized by sheer white chalk walls interspersed with flint nodules. Marine fossils are frequently exposed at the base of the cliffs due to ongoing erosion. The area serves as a natural barrier protecting the low-lying marshes of the Hable d'Ault behind it.
The viewing platform near the Rue de Saint-Valéry looking south toward the colorful villas of Mers-les-Bains.
Stay behind all safety barriers as the cliff edges are unstable and prone to sudden rockfalls.
Wear sturdy, closed-toe hiking shoes to navigate the loose shingle and uneven coastal trails.
Check local tide tables before descending to the beach to avoid being trapped against the cliffs.
Do not attempt to climb the cliff face or walk too close to the edge, as chalk is highly porous and prone to crumbling.
Avoid approaching the cliff base during heavy rain or wind, as the risk of rockfalls increases significantly.
