Longyou Grottoes

The Longyou Grottoes, near Shiyan Beicun village in Longyou County, Quzhou, are a cluster of enormous man-made sandstone caverns discovered in 1992 when local farmers pumped water from what had appeared to be an ordinary pond, revealing chambers up to 30 meters deep whose origin, builders and original purpose remain undocumented in any surviving historical record. Visitors descend covered walkways and staircases into several of the largest excavated caverns, where tool marks covering the walls and ceilings in regular parallel patterns are preserved much as they were found, alongside carved reliefs of fish, horses and birds on some chamber walls. Because no written record explains who carved the caverns or why, on-site displays present several competing theories, from quarrying to a hidden imperial project, without settling on a definitive answer, which is itself part of the site's appeal. A visit takes one and a half to two hours, covering four or five of the accessible caverns connected by walkways, including one chamber that hosts an underwater light-and-sound show recreating how the site looked when still flooded. The caves maintain a cool, damp interior year-round regardless of the surface season, so a light layer is useful even in summer. Weekday visits are considerably quieter than weekends, when tour groups from nearby Quzhou and Hangzhou increase foot traffic on the caverns' walkways.