Arcachon Bay (in French, the Bassin d'Arcachon, and known locally simply as "le Bassin") is a bay of the Atlantic Ocean on the southwest coast of France, situated between the Côte d'Argent and the Côte des Landes, in the region of Aquitaine. The bay covers an area of 150 km² at high tide and 40 km² at low tide. Some of its geological features are natural preservation areas.
The general shape of the Bassin d'Arcachon is that of an equilateral triangle pointing north, the southwest corner of which is open to the sea, between Cap Ferret and the town of Arcachon (more specifically, its suburb Pyla-sur-Mer), through a 3 km narrow channel (Les Passes). On the north shore is the town of Arès, then Andernos-les-Bains on the northeast. Just south of the entrance is The Great Dune of Pyla. Nearly in the middle of the bay is a very particular island: L'île aux Oiseaux (Isle of the Birds).
The Bassin still has a link to the sea perhaps because of the Eyre river that runs from the Landes forest and has its mouth (Delta de l'Eyre) in its southeast corner. Otherwise the Bassin would have become blocked by the sandbanks built up by the tides.
Arcachon (French: [aʁ.ka.ʃɔ̃] ; Arcaishon in Gascon) is a commune in the Gironde department in southwestern France.
It is a popular bathing location on the Atlantic coast 55 kilometres (34 mi) southwest of Bordeaux in the Landes forest. It has a fine beach and a mild climate said to be favourable for invalids suffering from pulmonary complaints.
Arcachon is known for the "Arcachonnaise", the local name for an Arcachon villa, which is the architectural style of many of the older houses built there. It is a type of Victorian architecture, and was criticized for generations, but is now considered to be charming.
The town of Arcachon is 150 years old. Not long before 2 May 1857, when Emperor Napoleon III signed its official "birth certificate", it was just a forest of pine trees, oaks and strawberry trees (arbutus), with no road links, and home - mostly when the weather was expected to be warm, and more in wood huts than in real houses - to fewer than 400 people, mostly fishermen and peasants. In earlier years, when some hygienists began to recommend sea bathing, three sea establishments were laid out by some entrepreneurs especially for the Bordeaux bourgeoisie and other wealthy people. This was the beginning of a new lifestyle, and some of the locals got the opportunity to claim their independence from La Teste-de-Buch, which owned their properties, in order to found a "free" new town, Arcachon.