A tulou , or "earthen building", is a traditional communal residence found in Fujian Province South China, usually of a circular configuration surrounding a central shrine. These vernacular structures were occupied by clan groups.
Although most tulou were of earthen construction, the definition "tulou" is a broadly descriptive label for a building type and does not indicate construction type. Some were constructed out of cut granite or had substantial walls of fired brick. Most large-scale tulou seen today were built of a composite of earth, sand, and lime known as sanhetu rather than just earth. The tulou is often three to four stories high. Often they would store food on the higher floors.
Due to their unorthodox and strange appearance from the outside they were once mistaken for missile silos by the Americans during the cold war.
The noted Fujian Tulou, designated as UNESCO World Heritage site in 2008, is a small and specialized subgroup of tulou, known for their unique shape, large scale, and ingenious structure. There are more than 20,000 tulou in southern Fujian. Approximately 3,000 of them are Fujian Tulou, that is 15% of tulou belongs to Fujian Tulou category.