Perched on a cliff top between two rivers, the ancient and abandoned city was in a perfect location to protect itself from attack. The remains of the buildings show the inhabitants built houses right into the rock and then used mud bricks to form other walls. There were windows and shelves carved into the rock. You climb to the top via a steep walkway, and then can wander around the ruins. All of the signs are in Chinese and Arabic, so it is helpful to have a tour guide.
The most fascinating part for me was the ruins of the ancient Buddhist Monastery. Our guide told us that if we walked around the center stone where the giant Buddha used to sit, that a wish would be granted. So we walked around the stone 3 times in the very hot heat (90F+), and then I made a wish.