Moon Hill, Natural arch in Yangshuo County, China.

Moon Hill is a karst hill south of Yangshuo, across the Jingbao River along China National Highway 321. Its pale grey and tan limestone face is pierced by a roughly 50-metre-high semicircular arch, the remnant of a cave formed in the phreatic zone. The hill reaches 380 m in elevation, 230 m above the surrounding land, and is 410 m long.

The arch formed over thousands of years as water dissolved passages through the limestone layers. This slow geological process carved the opening that now defines the local landscape.

The name 月亮山 (Yueliang Shan) means "Moonlight Mountain", after the semicircular hole that resembles a moon. Vendors selling souvenirs and refreshments often follow climbers up and down the path. Since 2019 the annual Yangshuo climbing festival in late October has drawn climbers to the hill's routes.

The climb involves stone steps arranged in sections to reach the upper viewing platforms. Sturdy footwear is important since the steps can be slippery, especially when wet from rain or morning moisture.

The opening looks entirely different depending on where you stand and the time of day, sometimes resembling shapes other than a moon. This optical transformation makes each visit interesting because you keep discovering new perspectives.