Huajia Karst Depression

　　Huajia Karst Depression is situated 3 kilometers northeast of Huajia Township, Shuicheng County. The elliptical karst depression has a major axis diameter of 700 meters at the top and 250 meters at the bottom, with a depth of 250 meters. It formed within Middle to Upper Carboniferous carbonate rocks. It is a type of collapsed sinkhole—also known as a doline (the transliteration), or commonly referred to locally as a "tiankeng" (heavenly pit) or "mawo" (pit). Due to collapse, it often features steep rock walls at the top. This landform is a closed negative terrain created when the roof of a large cave in the saturated zone collapses at the surface. It is often a natural window into an underground river, or may have a subterranean stream passing beneath the collapsed debris at the bottom. It is one of the largest types among various dolines or sinkholes. Shuicheng’s Huajia Karst Depression is a super-large sinkhole adjacent to Liuche River Canyon, known locally as Yangtian Mawo. It stretches 520 meters east-west and 950 meters north-south, with the bottom lying at an elevation of 1,225 meters. Its maximum depth is 257 meters, and the minimum depth is 185 meters, giving it a tadpole-like shape. The opening area of the sinkhole is 35.49 × 10⁴ square meters, the largest in China. The bottom is flat, covering an area of 6 × 10⁴ square meters, and has been converted into farmland. The surrounding inner walls are terraced, with steep cliffs above. About 500 meters south of the sinkhole lies the Liuche River, and just 100 meters from the top of the canyon’s steep cliff. Cave openings can be found on the cliff face, with the river surface sitting at an elevation of around 800 meters.

　　 Tip: To get from downtown to Huajia Karst Depression, take the Shuipan East Line’s fourth-grade oil road for 120 kilometers, then walk for 15 minutes to reach the site. The fare is 20 yuan per person. Currently, the Shuicheng–Puan long-distance bus passes nearby. At night, you can stay at local farmstead guesthouses in Huajia and enjoy rural cuisine.