Rock Paintings of the Sierra de San Francisco by Els Slots
We packed in for a camping trip with local guides, mules, and donkeys. The terrian is rugged and the views are out of this world. I managed to stay a day in a fresh water lagoon which I affectionitly call the viper pit. You do need a guide, and the hikes are always up, and the shade in the shelters are a great place to mediate and view the colorful panels. You could stay a week and still need more time. Try to visit when it is NOT summer.