Barbed wire, electric fences, thousands of armed soldiers, and an estimated seven million landmines run along what much of the world sees as the southern part of Morocco. But this strip of land is actually the disputed territory of Western Sahara, a swath of ungoverned desert just south of Morocco and northwest of Mauritania.

This war-torn territory is divided by the Moroccan Wall, a 1,600-mile-long, 10-foot-tall fortified berm, or sand wall. At 16 times longer than the Berlin wall was, the Moroccan Wall, also known as “the Berm,” is one of the largest active military barriers. Landmines dot the length of the fortification, making it also the longest minefield in the world.

The portion of land to the west of the wall, along the Atlantic Ocean, is controlled by Morocco. The eastern side is governed by the Polisario Front, a Sahrawi liberation movement. The fight for Sahrawi independence is what drove Spain, which had ruled Western Sahara for more than 90 years, out of the region in 1976. When Spain withdrew, Morocco took over the Atlantic coast and Mauritania the eastern portion, which was eventually overtaken by Sahrawi fighters.

Morocco began building a wall through the territory in 1981 to keep out guerilla fighters and refugees from the Sahrawi Arab Democratic Republic. The barrier was completed in 1987, and though hostilities officially ended in 1991, the wall is still heavily guarded with radar and other surveillance equipment. Still, the Polisario Front has occasionally been able to successfully burrow under the structure.

The landmines along the berm have caused many deaths and casualties among Sahrawi civilians, most of whom live in refugee camps on both sides of the wall. Since 2008, thousands of Sahrawi refugees and international human rights activists have gathered at an annual demonstration called The Thousand Column and created a human chain to protest the wall and demand its demolition.