Longyou Caves, Ancient man-made caves in China.
The Longyou Caves are an extensive, magnificent and rare ancient underground world considered in the history of Chinese architecture.
They were carved by human hands during the Qin Dynasty (221-207 BCE).
The caves have become a popular tourist attraction, known for their high historical and cultural values.
The caves are located in the Zhejiang province, near the village of Shiyan Beicun on the Lan River.
Despite their size, layout, and the effort involved in their construction, they remain shrouded in mystery with no record of their construction.
Location: Longyou County
Source: Wikimedia