The Moroccan Wall of Western Sahara is an approximately 2,700 km (1,700 mi) long structure, mostly a sand wall (or "berm"), running through Western Sahara and the southeastern portion of Morocco. It separates the Moroccan occupied, and controlled, areas (Southern Provinces) and the Polisario-controlled areas (Free Zone, nominally Sahrawi Arab Democratic Republic) that lies along its eastern and southern border.
According to maps from the United Nations Mission for the Referendum in Western Sahara (MINURSO) or the UNHCR, part of the wall extends several kilometres (a few miles) into internationally recognized Mauritanian territory.
The fortifications lie in uninhabited or very sparsely inhabited territory. They consist of sand and stone walls or berms about 3 m (10 ft) in height, with bunkers, fences and landmines throughout. The barrier minebelt that runs along the structure is thought to be the longest continuous minefield in the world. Military bases, artillery posts and airfields dot the Moroccan-controlled side of the wall at regular intervals, and radar masts and other electronic surveillance equipment scan the areas in front of it.
The following is one observer's description of the Berm:
Physically, the berm is a 2 m (6 ft 7 in) high wall (with a backing trench), which rides along a topographical high point/ridge/hill throughout the territory. Spaced out over every 5 km (3.1 mi) are a big, small and medium base, with approximately 35–40 troops at each observation post and groups of 10 soldiers spaced out over the distance as well. About 4 km (2 1⁄2 mi) behind each major post there is a rapid reaction post, which includes backing mobile forces (tanks, etc). A series of overlapping fixed and mobile radars are also positioned throughout the berm. The radars are estimated to have a range of between 60 and 80 km (37 and 50 mi) into the Polisario controlled territory, and are generally utilized to locate artillery fire onto detected Polisario forces. Information from the radar is processed by a forward-based commander, who contacts a rear-based artillery unit.