The grottoes are one of the main reasons to visit Datong. These stunning statues in the cave walls are absolutely mind-blowing and worth seeing. Although the intenrnet often says it takes 3 hours to see it all, you can actually view and appreciate them all in under 1,5 hour if there are no queues ( I went around opening time). I would highly recommend them, I think for quieter times go int he morning g, but for better lighting for pictures go int he afternoon!