Sandstone mesas rising to 3,000 m (9,840 ft) run through the center of Mauritania, from the northern frontier to the Sénégal Valley. Because rainfall is scarce, settlement is restricted to oases, where springs emerge at the foot of surrounding escarpments. Passengers and cargo are loaded onto a small boat at Rosso on the Sénégal River, Mauritania’s only river. The river forms Mauritania’s southern border with the country of Senegal and empties into the Atlantic Ocean at the town of Saint-Louis. Most of Mauritania’s people live in the fertile areas of the extreme south, and the highest concentrations are along the Sénégal.
On a street in Kîfa, a town in south central Mauritania, people in traditional West African garments walk in the evening light. Most people in Mauritania are Moors (of mixed Arab and Berber ancestry), many of whom lead a nomadic existence.