Because the Dead Sea, on the boundary between Israel and Jordan, is the lowest body of water on Earth’s surface, any water that flows into it has no outflow. It is called “dead” because its extreme salinity makes impossible any animal or vegetable life except bacteria. Fish introduced into the sea by the Jordan River or by smaller streams die instantly. The only plant life consists primarily of halophytes (plants that grow in salty or alkaline soil). The concentration of salt increases toward the bottom of the lake. The water also has such a high density that bathers float on the surface easily.