There are two contending theories about the origin of the low elevation of the Dead Sea. The older theory is that it lies in a true rift zone, an extension of the Red Sea Rift, or even of the Great Rift Valley of eastern Africa. A more recent theory is that the Dead Sea basin is a consequence of a "step-over" discontinuity along the Dead Sea Transform, creating extension of the crust with consequent subsidence.
The Dead Sea is a salt lake situated between Israel and the West bank to the west, and Jordan to the east. It is 420 meters (1,378 ft) below sea level and its shores are the lowest point on the surface of the Earth on dry land. The Dead Sea is 330 m (1,083 ft) deep, the deepest hypersaline lake in the world. It is also the world's second saltiest body of water, after Lake Assal in Djibouti, with 30 percent salinity. It is 8.6 times saltier than the ocean. This salinity makes for a harsh environment where animals cannot flourish and boats cannot sail. The Dead Sea is 67 kilometers (42 mi) long and 18 kilometers (11 mi) wide at its widest point. It lies in the Jordan Rift Valley, and its main tributary is the Jordan River.
The Dead Sea has attracted visitors from around the Mediterranean basin for thousands of years. Biblically, it was a place of refuge for King David. It was one of the world's first health resorts (for Herod the Great), and it has been the supplier of a wide variety of products, from balms for Egyptian mummification to potash for fertilizers.
