🇨🇳 China · Rock-cut
Longyou Grottoes
Warring States to Han (contested) · Yue–Wu contested; possibly Chu or Han
Mystery siltstone quarry silos 30×40 m 10–35 m deep with cavetto walls, 1992 flooded rediscovery.
🇨🇳 China · Archaeological wonder
Longyou Caves
Warring States to Han (~300 BCE – 100 CE; debated) · Yue / early Han Chinese
Twenty-four enormous man-made siltstone caverns rediscovered in 1992 after 2,000 years of siltation, each a single chamber 10–30 m high hewn with chisels that left uniform parallel tooling covering…