al-Baḥr l-Mayyit, "Dead Sea") is a salt lake 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 380 m (1,247 ft) deep, the deepest hyper saline lake in the world. It is also one of the world's saltiest bodies of water, with 33.7 percent salinity. It is 8.6 times saltier than the ocean. Experts say that it is almost ten times saltier than the Mediterranean Sea (34% salt versus 3.5% for the Mediterranean). This salinity makes for a harsh environment where animals cannot flourish. 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. Biblical, 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. People also use the salt and the minerals from the Dead Sea to create cosmetics and herbal sachets.
In Arabic the Dead Sea is called al-Bahr al-Mayyit ("the Dead Sea"), or less commonly baḥr lūṭ (بحر لوط, "the Sea of Lot"). Another historic name in Arabic was the "Sea of Zoʼar", after a nearby town. In Hebrew, the Dead Sea is Yām ha-Melaḥ , meaning "sea of salt," or Yām ha-Māvet (ים המוות, "sea of death"). In antiquity it was sometimes referred to as Yām ha-Mizraḥî (ים המזרחי, "the Eastern sea") or Yām ha-‘Ărāvâ (ים הערבה, "Sea of the Arabah").
The Dead Sea runs between the East Anatolian Fault zone in Turkey and the northern end of the Red Sea Rift offshore of the southern tip of Sinai. There are two contending hypotheses about the origin of the low elevation of the Dead Sea. The older hypothesis 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.
According to geological theory, approximately two million years ago the land between the Rift Valley and the Mediterranean Sea rose to such an extent that the ocean could no longer flood the area. Thus, the long bay became a lake.
The first such prehistoric lake is named "Lake Gomorrah." Lake Gomorrah was a freshwater or brackish lake that extended at least 80 km (50 mi) south of the current southern end of the Dead Sea and 100 km (60 mi) north, well above the present Hula Depression. As the climate turned more arid, Lake Gomorrah shrank and became saltier. The large, saltwater predecessor of the Dead Sea is called "Lake Lisa n."
From 70 000 to 12 000 years ago the lake level was 100 m (328 ft) to 250 m (820 ft) higher than its current level. This lake, called "Lake Lisa n", fluctuated dramatically, rising to its highest level around 26,000 years ago, indicating very wet climate in the Near East. Sometime around 10 000 years ago the lake level dropped dramatically, probably to levels even lower than today. During the last several thousand years the lake has fluctuated approximately 400 m (1,310 ft) with some significant drops and rises. Current theories as to the cause of this dramatic drop in levels rule out volcanic activity, therefore it may have been a seismic event.