Mauritania - Topography

There are three distinct geographic regions in Mauritania: a narrow belt along the Senegal River valley in the south, where soil and climatic conditions permit settled agriculture; north of this valley, a broad east-west band characterized by vast sand plains and fixed dunes held in place by sparse grass and scrub trees; and a large northern arid region shading into the Sahara, advancing south several kilometers each year, and characterized by shifting sand dunes, rock outcroppings, and rugged mountainous plateaus that in a few places reach elevations of more than 500 m (1,640 ft). The high point, Mount Ijill at about 915 m (3,002 ft), is near Fdérik. The country is generally flat.