The Dead Sea is awesome, and I highly recommend it.
We all remember from 10th grade geography that the Dead Sea shore is the lowest land on earth, 400 meters below sea level. What I didn't realize was that there's a whole basin there, a valley like a huge ditch in the earth ~10 miles across and over 100 miles long.
There's a -- not quite a cliff. An escarpment. Coming from the east, the main road from Amman goes down it in a long series of switchbacks. Just as you're going over the edge, a huge vista opens up in front of you: the ground dropping away, a narrow stripe of green that marks the river Jordan, the Dead Sea huge off to one side, the opposite escarpment (which is a bit lower) ten miles away dead ahead. And in the very far distance, a faint gleam in the haze: Jerusalem. It's what Moses saw from Mount Nebo. Which, by the way, is just a few hundred yards over to your left.
And just around this point, as the road noses downwards and the view opens up, you spot a little marker off to one side: Sea Level.