The Mogao Caves near Dunhuang is one of the most breathtaking places I’ve ever visited. Unfortunately, photography is forbidden — you have to check in your camera at the gate — so it’s hard to explain why this stop left such an impression.

In 366 A.D., a monk saw a vision of a thousand Buddhas in the rays of light sparkling in the cliffs. He began carving there and through 10 centuries, other pilgrims added carvings and murals to honour Buddha and ensure their own safe journeys.

More than 450 caves were carved out of the rocks. As one of the world’s most valuable collections of Buddhist art, the caves feature perfectly preserved murals, detailed carvings and giant statues.

Several dozen caves are open to the general public and all are locked behind doors to keep out the elements. Visitors must be escorted by cave guides at all times. Besides, they’re the only ones with keys.

We trooped from the sunlight into the darkness of cave #96. I saw the curve of some gigantic knees and drapery. I looked up and realized I was staring at a stunning nine-storey high statue of Buddha. In a cave.

The ceiling of another featured thousands of painted buddhas. Even with the bright daylight outside, they could be seen with only flashlights.

The guide explained that painters could not work by candlelight to do the delicate ceiling detail, since the smoke would have ruined their work. Instead, they used mirrors to reflect light into the cave.

The mandatory guide system annoys many people. Visitors can only enter in groups of 20 or more. So if you’re travelling solo or as a couple, you must wait to join others who speak the same language. Plus they charge more for English-speaking guides.

The caves you actually visit depend on which ones your guide feels like opening. Luckily, our group was made of up major nerds who asked lots of questions. That made our guide happy, so she let us into a few caves regular tourists don’t normally see.

But she didn’t show us the caves with the explicit tantric scenes. That costs extra.