The area lies in North Africa, on the coast of the Atlantic Ocean. It is bordered by Morocco in the north, Algeria in the east (they have 42 kms of common boundary) and Mauritania from the east and south. Its area is 266,000 square kilometres. Just like in most African countries, the borders were marked out by the colonial powers by ratifying different treaties, agreements. The borders of Western Sahara were regulated and marked out by the agreements signed by Spain and France in 1900, 1904 and 1912. Its lowland area is plain, sandy and rocky, with a few hills in the southern and north-eastern parts. These hills are at an altitude of not more than 400 metres2. Its lowest point is Sebjet Tah, 55 metres below sea-level, while the highest is a 721 metre high hill, which has no official name. Western Sahara can be divided into three main regions.