I've only been to two of the Nabatean cities in the Negev: Shivta (Sobota) and Avdat (Oboda). Both are well worth a visit if you are into desert landscapes and antiques. Sobota is the better preserved one among these two. It clearly shows the original urban structure and features two churches. A nearby fruit garden uses traditional agriculture (solely based on rain water) in order to reconstruct the Nabatean way of life in this arid climate. Sobota is inaccessible if you don't arrive by car and is usually empty. During my visit here me and my friends were the only visitors although we stayed for two hours! Add the already isolated desert environment and you get a feel of what it is like to live here.

Oboda is a larger complex and also has the advantage of being situated atop a hill on the road between Beer-Sheva (Bersheba) and Eilat (easily accessible with public transport). It also includes a reconstructed Nabatean house worth a visit. The surroundings are abundant with caves which the Nabateans used to exploit for various purposes. The nearby Oboda Spring is of exceptional natural beauty.

If you come down here don't miss the nearby Ramon cirque by any chance. It is world unique.