When you approach a karst cave in Southwest China's Guizhou, you might not notice the stalactites in the dark over the glare of floodlights and the roar of cheering.

Inside Fengming Cave in Yanhe Tujia autonomous county, a full-size basketball court sits under a vaulted ceiling, surrounded by packed stands and streamers. A late-August basketball tournament drew teams from Chongqing and the provinces of Hubei, Hunan and Guizhou, attracting more than 40,000 people to Yanhe's Cuantang village. The influx prompted local officials and villagers to begin planning tourism and other projects around the county's cave network.

Guizhou sits atop extensive karst terrain. Heavy rainfall and a humid climate in Yanhe have helped form and preserve numerous caves. Local authorities said the county has recorded more than 1,000, some of which now figure in visitor service plans.