Datong rewards visitors who come prepared for a place that is simultaneously ancient and heavily restored. The Yungang Grottoes are unmissable — one of the great Buddhist art sites in the world. The old walled city has been reconstructed in the last two decades, and while the result is sometimes too clean to feel authentic, the temples and the Nine Dragon Screen within the walls are genuine. A day trip to the Hanging Monastery at Hengshan is worth the effort.