Located on the south side of Guang Ming Mountain, this cave is about 700,000 years old, formed as the result of constant water erosion. Reed Flute Cave is the largest and perhaps the most spectacular of the limestone caves in Guilin. Hidden halfway up a mountain, it got its name from the reed that grows near the entrance, which makes excellent flutes. The cave is known as a "palace of natural art." Along its zigzag path are the unusual stalactites and stalagmites that, with colored lighting, look like coral, agate, amber, or jade—a wonderland of formations resembling or chards, gardens, or whatever else you care to imagine