Guyaju Caves

China's largest ancient cliff dwelling complex, carved into the slopes of Tianhuang Mountain in Yanqing District, Beijing. The site contains over 350 chambers with rooms featuring carved kang bed-stoves, flues, windows, and lampstands, with some apartment complexes having up to eight rooms suggesting social hierarchy. Discovered in 1984, the caves' origins remain mysterious -- theories attribute them to the Kumo Xi tribe during the Five Dynasties Period (907-960), a Tang Dynasty granary, or Han Dynasty garrison. The sophisticated construction required significant organization and manpower.