To the left shows a typical rock wall in the machtesh.  You can clearly see the layers of different colored stone, a geologist's dream. 
As you can see, we were on a jeep tour, which are popular in the negev.

To the right is our group.  That's me on the left. Alisa wasn't with us on this jeep trip. She joined us the next day.

The pictures below are from our hike through the Avdat wadi.  A wadi is a dry
river bed in the desert.  It has flowing water only when it rains.  In this part of
the world, it only rains in the winter, and then not very much.  when flooding
often occurs and can completely change the landscape.  This is a rare spot
which has water all year round.

On the left is a poplar grove above the water in the avdat wadi.  This is still the desert.

Here is a climb up a mountain path on the rim of the canyon made by the wadi. That's Alisa in the lower right corner. This climb brought us to the falls above the wadi.

So, If you come to Israel, don't miss the Mitzpeh Ramon area in the
Negev desert.