the Negev dessert in the south of israel is very nice,there are 5 erosion craters,if you walk the israel national trail you go trough 3 of them.you will see different animals but wolfs,leopard you will not see because they stay away from the weird nutty humans that walk trough the dessert :-).
you can sleep everywhere you want but there are night camps where you are more likely to meet people with cars. there is 85% of the time no shade to hide when its hot like helllll.
and in the night there is a lot of chilly wind that hides stil the evening but during the day hides to tease you.
walked for 2 weeks in the Negev and i whent a little nuts from the heat even did a rain dance but no luck was 2.5 months in Israel august,September and October , go in winter or spring not in summer is my advice.