Tulou, meaning earth building, is the most extraordinary type of Chinese Hakka's rural dwelinngs in the mountainous areas of Fujian, in south China. Escaping from the war and disaster, the Hakka were originally moved there from northern China since 12th century. They settled down in Fujian province and developed groups and groups of the unique earth building between the 12th to the 20th centuries.
A Tulou is usually a large, enclosed and fortified earth building. With a round or square configuration, it is designed as a solid fortress for the Hakkas' living and safety in the area of undesirable mountains. The building, usually from three to five stories, is constructed by very thick load-bearing rammed earth walls. The outer walls are formed by compacting earth with stone, bamboo pieces, wood block and other readily-available materials and are thick up to six feet (≈2m). The reinforced outer structure are protective for wind and earthquake and make a well-ventilated environment cool in summer and in winter.
The earth building, typically no windows at ground floor, has only one gateway guarded by 4-5 inch thick wooden doors with an outer wrap of iron plate. Each floor serves a different function, the first hosts a well and livestock, the second is for food storage and the third and higher floors are living spaces. More often, the top floor of these earth buildings has gun holes for defensive purposes. The largest Tulou houses up to 80 families and the smallest one for 6 families.
With total number of 46 sites, Tulou can be found mostly in south western Fujian provinces. They are Gaobei cluster, Hongkeng cluster and Chuxi cluster in Yongding county, Tianluo cluster and hekeng in Nanjing county, Dadi tulou cluster in Huaan county. Zhenfu Tulou in Yongding is a 'prince' among them. Tulou buildings have been inscribed in 2008 by UNESCO as a World Heritage Site and praised as 'exceptional examples of a building tradition and function exemplifying a particular type of communal living and defensive organization in a harmonious relationship with their environment'.