The Saint Louis region of Senegal sits just off the border with Mauritiania. Famous for its cast iron bridge, put in by French colonialists in the 19th century, it is close to the Djoudj National Park, home to thousands of birds, some indigenous to the area. The centre of the town is concentrated on the island of St. Louis and the sprawl continues in both directions. The north of the city has a long and sparse beach.