Mystery surrounds more than 100 caves on the sheer cliff face of a peaceful gorge in Yanqing district. (Source: China Daily)

Mystery surrounds more than 100 caves on the sheer cliff face of a peaceful gorge in Yanqing district.

There is no written record of the origin or history of the Guyaju cave complex in Zhangshanying town, 92 km north of Beijing. But they comprise the largest network of known cliff residences in the country.

The caves are a honeycomb of rooms of different shapes and sizes outfitted with doors, windows, kitchens and closets.

Some of the quadrangular rooms, ranging in size from 3 to 20 sq m, are interlinked with vertical passages, while horizontal passages connect others. Some of the "houses" feature two to three rooms, while others only have a single compartment.

Visitors who wander among the rooms will see tables, stools and even a kang (a traditional bed heated from beneath) carved from stone.

Any characters or murals that might have once covered the walls of the dwelling have vanished, leaving historians to scratch their heads about who lived here and when.

Some believe it was built in the Tang Dynasty (AD618-907), while others contend it was during the Liao Dynasty (AD916-1125).

Still others say it was a lair for bandits, or a military shelter, or a place for Xi tribe to hide during wartime.

But most agree the grottos are about 1,000 years old.

The most intriguing of these caverns contains a two-story stone house propped up by six intricately carved pillars.

One wing contains a small room with lampshades, hearths, closets and mangers all made of stone. The structures' windows and gates serve as eerie reminders that it was once a dwelling place for ancient inhabitants.

Different stories are connected with stone steps and stone ladders. From these, visitors can take in breathtaking panoramic vistas of the gorge area.

Editor：Wang Nan