The Dead Sea is a salt lake bordered by Jordan to the east and Israel and Palestine to the west. Its surface and shores are 429 metres below sea level, Earth's lowest elevation on land. The Dead Sea is 304m deep, the deepest hypersaline lake in the world. With 34.2% salinity, it is 9.6 times as salty as the ocean, and one of the world's saltiest bodies of water. This salinity makes for a harsh environment in which plants and animals cannot flourish, hence its name. The Dead Sea is 50 kilometres long and 15 kilometres wide at its widest point. It lies in the Jordan Rift Valley and its main tributary is the Jordan River.