Facing the majestic Dune du Pilat, between Cap Ferret and the Landes coast, stretches a land as fascinating as it is fragile: the Banc d'Arguin. A truly shifting island, it constantly changes face with the winds, tides and currents, offering visitors a landscape both wild and fleeting.
Born some 4,000 years ago from a marine transgression, the Banc d'Arguin today measures up to 4 km long and 2 km wide at low tide. But nothing here is fixed: this sandbank moves, breaks apart, recomposes, and will sooner or later disappear or migrate, replaced by a new formation. This instability makes it a real natural laboratory for geographers.
A national nature reserve
Listed as a nature reserve since 1972, the Banc d'Arguin is strictly protected. The rules are clear: no camping, no dogs, no picking, no litter. Some areas, reserved for bird nesting, are even fully off-limits to the public. In 2025, the rules were adjusted again: new sandy tongues to the south are now open for mooring, while certain northern zones are only accessible depending on the season.
The Banc d'Arguin is above all a bird paradise. Over 200 bird species are observed here, and it hosts the largest French colony of Sandwich terns. Other emblematic species nest or rest here during migration: oystercatchers, Kentish plovers, various waders.
Biodiversity doesn't stop there: seagrass beds, crustaceans, insects and fish make up an ecosystem of rare richness. In the surrounding waters, you regularly cross paths with dolphins, porpoises, sometimes even seals and sea turtles.
An accessible but fragile site
You can only reach the Banc d'Arguin by boat. Shuttles from the Dune du Pilat, Bay boats or private trips let you set foot on this moving sand. But access is limited and controlled: only certain sectors are open to walking and mooring, and always in line with reserve rules.
In summer, free guided visits are organized to raise public awareness of the site's history and fragility. Oyster farming and sea fishing take place here, but under strict control.
A history and a name loaded with symbols
The name « Banc d'Arguin » was given in the 19th century, as a tribute to another bank, the one in Mauritania, sadly famous for the wreck of the Méduse in 1816. Since then, the Arcachon islet has become a constant object of study and a major reference for protecting the Aquitaine coasts.
But this jewel remains fragile. Erosion and climate change inexorably reshape its form, while human visits add extra pressure. Preserving this site means protecting a unique natural balance, where the meeting of sand, ocean and birds composes one of the most iconic landscapes of the Atlantic coast.
The Banc d'Arguin isn't just a geographical curiosity: it's a living natural monument, a shifting heritage you discover with wonder but also with respect. At every tide, it redraws itself; at every visit, it tells a new story.
