Mogao special caves, Dunhuang
The eight caves on the public rotation are chosen for durability and crowd flow, not for quality. The special caves hold the best-preserved Tang and Northern Wei painting and sculpture at the site, and you see them with four or five people instead of twenty-five.

Mogao cave complex at Dunhuang · setting photograph, not a depiction of a private tour or package.
Picture your day
You buy the standard timed ticket, watch the two films at the Digital Exhibition Centre, ride the shuttle to the cliff face and do the normal eight-cave route with a guide. Then you present a separate special-cave ticket at a small kiosk inside the site and a second guide unlocks one or more caves that the general route never enters, among them Cave 45 with its Tang bodhisattva group, Cave 57, Cave 220 and Cave 275. Each cave is opened for your party alone or a handful of people, lit by the guide's torch, with no photography.
The access, explained
Genuinely closed to general admission. The Dunhuang Academy keeps roughly fourteen caves off the standard route (published lists name 9, 45, 57, 156, 158, 159, 217, 220, 254, 275, 320, 321, 322 and 420) and sells a per-cave supplement for them with a strict daily cap. Which caves open on a given day is decided by the Academy on conservation grounds, so no operator can promise a specific cave in advance. This is not a private guide on a public visit; it is a different door.
Planning the details
How to arrange it. Book the standard ticket on the official Mogao reservation system up to 30 days ahead using the passport you will travel on; the daily cap is about 6,000 in peak season. Special-cave supplements are sold on site only, at the kiosk, on the day, and commonly sell out before midday. A Dunhuang-based agency can queue for you but cannot pre-purchase them. No permit beyond the ticket.
When to go. Winter (Dec-Mar) is the only time special caves are reliably available on the day; from May to October they go early and the site is at capacity.
Indicative cost. Standard foreign-visitor ticket ¥258 Apr-Nov, ¥160 Dec-Mar, plus roughly ¥150-200 per special cave
Ask for written confirmation of the date, duration, guide language, transport, admission and cancellation terms. Any restricted access must be confirmed by the venue.
The setting, in pictures & film
Videos open on their publisher’s site. YouTube is unavailable in mainland China; watch before travelling.
Good to know
The access is real, the certainty is not. Agencies that quote a fixed price for named caves months ahead are selling something they do not control, and a few sell an ¥800-ish package that is their fee plus a guess at the supplement. Expect to be told on the morning which caves are open. Photography is banned in all of them, the lighting is a handheld torch, and if you are not already interested in Buddhist painting the standard route is enough.