Landes is a department in the Nouvelle-Aquitaine region, Southwestern France, with a long coastline on the Atlantic Ocean to the west. It als…Landes is a department in the Nouvelle-Aquitaine region, Southwestern France, with a long coastline on the Atlantic Ocean to the west. It also borders Gers to the east, Pyrénées-Atlantiques to the south, Lot-et-Garonne to the north-east, and Gironde to the north. Located on the Atlantic coast, it had a population of 413,690 as of 2019. Its prefecture is Mont-de-Marsan.