Book Mogao a month out — it is the one thing you cannot improvise

Full tickets are real-name, released about a month ahead on the official Mogao system, and sold out through the summer. The visit is guided only: two films at the visitor centre, then a bus to the cliff and eight caves with a guide, chosen for you, roughly two hours.

English-language groups run at set times, so pick a slot deliberately rather than taking the first one free. If the full tickets are gone, the emergency ticket sold on the day shows fewer caves and is worth having as a fallback. Winter has fewer visitors and more caves open.