Arcachon, a village of France, in the department of Gironde, 35 m. by railway W. S. W. of Bordeaux; pop. about 2,000. It is situated on a landlocked bay or lake (bassin d'Arcachon), about 60 m. in circumference, connected with the gulf of Gascony by a narrow strait. Since 1854 the village has been converted into a watering place by the Pereire family, who bought the surrounding woods and swamps, and drained part of the bay. Previous to the Franco-German war the visitors annually averaged 5,000. Persons suffering from diseased lungs are much benefited in winter by the mildness of the climate. The beach is very fine, and sea bathing attracts in summer many visitors. The pine woods extend almost as far as Bayonne, and abound with game.