It was a barrier to travel in the Biblical Times and still is. Just north of the Dead Sea on the western side of the Jordan River is the ancient ruin of Jericho.It was so positioned as to control travel in the times of the Bible. Joshua had to conquer it to enter the "Promised Land".Very few life forms grow in the "Dead" Sea, but salt has been harvested from it. Much of the water that drains into it from the Jordan River is now extracted before it reaches it.
(JGL pix)