Wadi Natrun

(Wadi en Natrun), a depression southeast of the Libyan Desert in the United Arab Republic west of the Nile Delta, 24 m below sea level. Wadi Natrun is about 40 km long and 3-8 km wide. It occupies a tectonic joint deepened by ancient river and wind erosion. Wadi Natrun has more than ten small salt lakes whose water contains trona (Arabic natron, a rare mineral), which is extracted.