Moon Hill (Chinese: 月亮山; pinyin: Yuèliàng Shān; lit. 'Moonlight Mountain') is a hill with a natural arch through it a few kilometers outside Yangshuo in southern China's Guangxi autonomous region. Moon Hill is part of the Guilin Mountains. It is so named for a wide, semicircular hole through the hill, all that remains of what was once a limestone cave formed in the phreatic zone. Like most formations in the region, it is karst. It is also a popular tourist attraction.