One of Palestine’s most unusual geological features is the Dead Sea. It is part of a deep north-south valley that extends along the Jordan River as far as the Gulf of Aqabah (north-eastern arm of the Red Sea) to the south. The Dead Sea, which is the lowest part of this valley, has a water level approximately 400 metres below sea level. It is about seventy-five kilometres long and fifteen kilometres wide. People in ancient times gave it the names Salt Sea and Dead Sea because it was extremely salty and, so far as they could see, nothing could live in it (Numbers 34:12; Joshua 3:16; cf. Ezekiel 47:8-9). (See also PALESTINE, sub-heading ‘Jordan Valley and Dead Sea’.)