Dunes D'Ecault, Protected coastal area in Pas-de-Calais, France.

The Dunes d'Écault cover 162 hectares in Saint-Étienne-au-Mont, rising to 90 metres where sand has piled against an old sandstone and marl cliff. Pale sand, dry grass and low shrubs give way to a steep eroded face showing tan and rust-coloured layers, with the flat sea beyond. The massif continues inland as the Forêt d'Écault.

The dune system began forming in the 17th century as sand movements shaped the landscape over time. Concrete bunkers built during World War II remain visible today as remnants of wartime occupation.

The site is managed by the Pas-de-Calais departmental council with the Eden 62 joint association, and the dunes belong to the Conservatoire du littoral. A dune house called Aréna organises guided visits and runs the site's protection. The long-distance footpath GR121 crosses the dunes, and marked trails continue toward the hamlet of Écault, the forest, Hardelot castle and the Condette marsh.

The area has clearly marked trails for walking, which visitors should stay on to protect the delicate vegetation. Dogs must be kept on leashes, and it is important not to damage or pick any plants.

The dunes are not free-standing: they formed by plastering themselves against an old sandstone and marl cliff, which is why the massif rises to 90 metres above the sea. The GR121 long-distance path crosses the site, and the Maison de la dune, called Aréna, organises guided visits.