Photo taken on Jan. 4, 2018 shows the stone stairs in a Hakka square enclosed house in Hepu County, south China's Guangxi Zhuang Autonomous Region. The well-preserved Hakka square enclosed house is considered as a "living fossil" of Hakka culture and architecture. Built in 1883, this house covers an area of 6,050 square meters. Its walls were made by the mixture of mud, lime, sand, sticky rice and brown sugar. The house still has residents today. (Xinhua/Zhang Ailin)