Low, low lake
© Dave/Adobe Stock
Its name means 'honey' in Arabic, but the waters of this Djibouti lake are far from sweet. Rapid evaporation here in the desert, combined with a lack of outflow, give Lake Assal a salinity level as high as 40%—ten times as salty as the ocean. Assal is even saltier than the Dead Sea and almost as low-lying: its surface more than 500 feet below sea level, it's the lowest-elevation point in Africa.