Analysis of information sources in references of the Wikipedia article "Western Sahara" in English language version.
For the past forty years, tens of thousands of Moroccan soldiers have manned a wall of sand that curls for one and a half thousand miles through the howling Sahara. The vast plain around it is empty and flat, interrupted only by occasional horseshoe dunes that traverse it. But the Berm, as the wall is known, is no natural phenomenon. It was built by the Kingdom of Morocco, in the nineteen-eighties, and it's the longest defensive fortification in use today—and the second-longest ever, after China's Great Wall
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