Buddhist painting and sculpture from the fourth century onward, in the dark on purpose. You see a small number of caves on a timed visit. Foreign visitors generally book the foreign-guest route and show a passport. Same-day hope is how people see the gift shop.
This is a historic site under extraordinary limits. The rules about lights, tripods, and touching are the conservation, not a mood.
Give it the half day. You will not see hundreds of caves. You will see a few properly.
Getting there
The visitor center first, southeast of town, then the official shuttle to the cliff. A taxi to the cliff gate is the wrong plan. Morning slots are the ones to want.
Staying nearby
Sleep in Dunhuang town. Leave for the visitor center with a margin. A desert camp the same morning is how you arrive sandy and late.