The ruins which compromise the Incense Route of the Negev mostly date back to the crusader era, even though the cities themselves are much older. That is why you will see Christian iconography and other symbols. The towns were part of a network of trading sites which extended from Oman, through Saudi Arabia, Jordan, and Israel. The Nabatean city of Petra was also part of the same trading network.

I visited Avdat and Shivta National Parks, which are pretty easy to reach by car. You could visit all of the sites by car on a day trip from Jerusalem or Tel-Aviv.