island city and seaport near the mouth of the Sénégal River, and rail terminus north-northeast of Dakar, Senegal. The island and city are connected to the mainland by a land bridge. Saint-Louis, founded in 1659, is the oldest colonial city on the western African coast and was the administrative capital of the French West African territories of Mauritania and Senegal. The establishment of Dakar (with a better port), the building of the railroad linking the two cities, the creation of a French West Africa headquarters at Dakar, and the completion of the Dakar-Niger railroad led to the decline of Saint-Louis. It is now a fishing centre, river-rail transfer point for the trade of the Sénégal valley, and home to Gaston-Berger University. Saint-Louis was designated a UNESCO World Heritage site in 2000. Pop. (2004 est.) 162,089.