People visit Fengyan cave in Guangnan County, southwest China's Yunnan Province, June 4, 2016. Nearly 300 people of 60 families used to live in Fengyan cave. Their houses and living accessories were kept intact after all the inhabitants moved out in 2000. Local government of Guangnan began repairing of the cave since beginning of this year to protect the site. (Xinhua/Chen Haining)

Photo taken on June 4, 2016 shows the inside view of Fengyan cave in Guangnan County, southwest China's Yunnan Province. Nearly 300 people of 60 families used to live in Fengyan cave. Their houses and living accessories were kept intact after all the inhabitants moved out in 2000. Local government of Guangnan began repairing of the cave since beginning of this year to protect the site. (Xinhua/Chen Haining)

Visitors push a stone mill within Fengyan cave in Guangnan County, southwest China's Yunnan Province, June 4, 2016. Nearly 300 people of 60 families used to live in Fengyan cave. Their houses and living accessories were kept intact after all the inhabitants moved out in 2000. Local government of Guangnan began repairing of the cave since beginning of this year to protect the site. (Xinhua/Chen Haining)

Photo taken on June 4, 2016 shows the inside view of Fengyan cave in Guangnan County, southwest China's Yunnan Province. Nearly 300 people of 60 families used to live in Fengyan cave. Their houses and living accessories were kept intact after all the inhabitants moved out in 2000. Local government of Guangnan began repairing of the cave since beginning of this year to protect the site. (Xinhua/Chen Haining)

Photo taken on June 4, 2016 shows current dwellings of residents used to live in Fengyan cave in Guangnan County, southwest China's Yunnan Province. Nearly 300 people of 60 families used to live in Fengyan cave. Their houses and living accessories were kept intact after all the inhabitants moved out in 2000. Local government of Guangnan began repairing of the cave since beginning of this year to protect the site. (Xinhua/Chen Haining)

A working staff member of Fengyan cave rests on a hammock in Guangnan County, southwest China's Yunnan Province, June 4, 2016. Nearly 300 people of 60 families used to live in Fengyan cave. Their houses and living accessories were kept intact after all the inhabitants moved out in 2000. Local government of Guangnan began repairing of the cave since beginning of this year to protect the site. (Xinhua/Chen Haining)

A visitor walks into Fengyan cave in Guangnan County, southwest China's Yunnan Province, June 4, 2016. Nearly 300 people of 60 families used to live in Fengyan cave. Their houses and living accessories were kept intact after all the inhabitants moved out in 2000. Local government of Guangnan began repairing of the cave since beginning of this year to protect the site. (Xinhua/Chen Haining)