Canyon de Chelly

If you don't mind dry camping you might try Chaco Canyon in NM. We have visited most of the ancient sites and this is in our opinion the most impressive. Very rough slow drive in, from north or south route, never very crowded was a no reservations but plenty of room even for bigger rigs. A small store but only drinking water available Camp very close to the ruins. When the sun goes down the canyon becomes almost mystical. Unlike a lot of the others this one is largely untouched.