Tulou, ancient wisdom preserved in earthen architecture

The Fujian tulou, or earthen buildings, are variously-sized circular and rectangular buildings mostly set among rice, tea and tobacco fields, and some can house up to 800 people.

Several stories high, the multifamily communal living structures were first designed for defense purposes. In 2008, the buildings became well-known after 46 of them, constructed between the 15th and 20th centuries, were inscribed on UNESCO's World Heritage List as a unique residential architecture of Fujian province.

As the saying goes: "People who haven't seen the Tianluokeng tulou cluster haven't seen the real tulou." Lying halfway up the mountains of Nanjing county, the Tianluokeng cluster is the most iconic of the Fujian tulou. It's among the UNESCO-listed ones, alongside the Hekeng tulou cluster, Huaiyuanlou and Heguilou - the largest rectangular one, with five stories built on the soft swamp.