Earthen houses represent a vernacular architecture specific to Jiangxi, Fujian and Guangdong provinces following the flow of the Hakka people from central China to the South. As most Hakka resided in mountains, communal houses made of compacted earth were built to provide protection against bandits and wild animals. The older examples of this style of construction consist of interior buildings enclosed by huge peripheral ones holding hundreds of rooms and dwellers. With all the halls, storehouses, wells and bedrooms inside, the huge towerlike building functions almost as a small fortified city. Earthen houses are made of earth, stone, bamboo and wood, all readily available materials. After constructing the walls with rammed earth, branches, strips of wood and bamboo chips were laid in the wall as “bones” to reinforce it. The end result is a well lit, well-ventilated, windproof, quakeproof building that is warm in winter and cool in summer. Over twenty thousand of these houses still stand today, ten of which are over 600 years old. The oldest one, “Fu Xing Lou” in Hu Le town, was constructed over 1,200 years ago and is regarded as a “living fossil” of the construction style of central China. The tulou located at the border of Yongding County and Nanjing County is the perfect example of this style of construction and it is here that there are most earthen houses. Most of the nominated properties are located in this area. Yongding County is located in the mountainous area of the Longyan City jurisdiction, in the western part of Fujian Province. There are many architectural designs of tulou in this area with a well-concentrated distribution of clusters. The most common designs are rectangular, round, triangular, pentagonal and octagonal. Other designs also include D-shaped and 日(the Chinese character for “sun”).