Mogao Caves

The first thing you notice is the dryness. The air carries fine grit, and the light off the desert is pale and hard. In front of you, a long cliff face of packed gravel and sand runs north to south. Hundreds of small dark openings sit in rows along it, like windows in a building with no walls. Poplar trees line the dry riverbed below. Behind you, the dunes of the Gobi rise in soft yellow ridges. This is the Mogao Caves, one of the great treasure houses of Buddhist art.

You are about twenty-five kilometres southeast of the oasis town of Dunhuang. Dunhuang sits within Jiuquan, in the far west of Gansu Province. For centuries, this oasis was a vital stop on the Silk Road. Here, the northern and southern routes around the Taklamakan Desert met before turning east into China. Merchants, monks, soldiers and pilgrims all passed through. Many of them left something behind in this cliff — a prayer, a donation, a painted cave.

The traditional story of the first cave is a beautiful one. According to an old account recorded on a stone tablet, a monk named Lezun came here in the fourth century. At sunset, he saw the cliff glowing gold, as if a thousand Buddhas were shining from it. He decided to carve a meditation cell on this spot. Whether the vision happened, nobody can say. But cave building did begin around this time, and it continued for roughly a thousand years.

The numbers are hard to picture. Around 735 caves survive along the cliff. Close to five hundred of them hold murals or sculpture. Together, the painted walls cover about 45,000 square metres. That is enough painting to stretch for many kilometres if you laid it out in a single band. There are also more than two thousand painted sculptures. The work spans dynasties from the fourth century to the fourteenth century.

Here is a detail most visitors miss. The cliff is made of conglomerate — loose gravel cemented together with sand. It crumbles too easily for fine stone carving. So the sculptors here did something different. They built wooden frames, wrapped them in reed and straw, and then shaped the figures from layers of clay. Finally, painters coloured them. Every statue you see inside is fragile, sculpted clay, not carved rock.

The walls tell stories. Many murals show scenes from the life of the Buddha and from earlier lives in Buddhist tradition. Others show paradise scenes, with palaces, lotus ponds, musicians and dancers. Look for the flying figures called apsaras, or feitian in Chinese. These are heavenly beings who float through the air with long ribbons trailing behind them. In the early caves, they look stiff and heavy. In later caves, they become light and graceful, swooping across the ceilings.

The murals also show daily life in great detail. Painters added farmers with ploughs, merchants with camels, wedding feasts, hunters and boatmen. Donors often had their own portraits painted along the lower walls. These rows of richly dressed men and women give historians a rare view of clothing and customs across many centuries. In some caves, the donors grow larger over time, a quiet sign of how wealthy local families wanted to be remembered.

The second surprise is about colour. Some faces in the murals look dark grey or almost black. Visitors sometimes assume the painters chose this. In fact, many of these areas were painted with lead-based pigments that were once pink or flesh-toned. Over centuries, the pigment changed chemically and darkened. So the somber faces you see today were bright and warm when the artists finished them.

Then there is the most famous discovery here. In 1900, a Taoist monk named Wang Yuanlu was clearing sand from one cave. He found a hidden doorway behind a painted wall. Inside was a small chamber packed with tens of thousands of manuscripts, paintings and textiles. This room is now called the Library Cave, or Cave 17. It had been sealed around the early eleventh century. The reason it was sealed is still debated.

The documents were written in many languages, including Chinese, Tibetan, Sanskrit and Uyghur. Foreign explorers soon arrived. Aurel Stein, working for the British, took a large collection in 1907. The French scholar Paul Pelliot followed in 1908. Today, much of this material is held in London, Paris and other cities far from Dunhuang. One famous item is a printed copy of the Diamond Sutra dated 868. It is the earliest dated printed book known.

At the northern part of the main cliff, you will see a tall red wooden façade with tiered roofs. This is the Nine-Storey Building, which protects Cave 96. Inside sits a giant seated Buddha more than thirty metres tall. The figure is so large that you must tilt your head far back to see its face. The building in front has been rebuilt several times, and today it is the shape most people picture when they think of Mogao.

Protecting the caves is a constant task. Sand, moisture and the breath of visitors all damage the paint. The Dunhuang Academy leads the conservation work, and it has worked with international partners on new methods. Visits are limited and carefully managed. Most people first see films at the digital exhibition centre, then take a shuttle to the cliff. A guide opens a selection of caves and uses a small torch to light the walls.

The UNESCO listing came in 1987, but the caves had long been a place of pilgrimage before that. For many centuries, people came here to pray, not to look. That feeling still lingers when the guide closes a heavy door and the cave goes dim. The paintings were made for lamplight, for slow eyes, for people who sat and waited.

As you walk back along the cliff, look up at the rows of doorways once more. Behind each one is a room someone paid for, someone painted, and someone hoped would last. Listen to the wind moving through the poplars and the soft crunch of grit underfoot. The desert is still close here, pressing at the edges. And somehow, these small painted rooms are still holding on.