Cavechat.org

This Giant Cave In China Has 100 People Living Inside, A Basketball Court And Even Had A School.

http://www.boredpanda.com/cave-village-miao-zhongdong-guizhou-china/

(one of the last two villages in caves in China. The other is somewhere in Yunnan Province)

http://avantgardica.blogspot.lt/2015/03/climbing-in-china-getu-redux.html