Landes, region, SW France. It is a vast, flat, nearly triangular tract of sand and marshland, stretching along the Atlantic coast for more than 100 mi (160 km) between the Adour River and the Médoc region and reaching inland as far as 40 mi (60 km). It thus covers most of Landes dept. and part of Gironde dept. and converges on Nérac (Lot-et-Garonne). Formerly, sheep grazing was the only occupation in this insalubrious region, but much of the land has been reclaimed through drainage and the planting of pine forests. Agriculture is progressing and lumber and resins are important products. The chief towns are Mont-de-Marsan, Dax, and Arcachon, a popular resort.