A tulou 土楼 or "earthen building", is a traditional communal residence in the Fujian province of Southern 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 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 famous Fujian Tulou, designated as UNESCO World Heritage site in 2008, is a small and specialized subgroup of tulou, and are 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 - by wikipedia.
Visiting tulou is a must if you are in Fujian or Xiamen. The scenery was beyond my expectation. The location is up at the mountains and it is impossible to visit this place on your own as you need to move from our place to another accompanied by a tour guide. The price we paid was worth the value of the tour.
What you see from the outside is totally a different picture inside. The first time I enter the tolou, my mouth open in surprise. It's amazing they have so many people staying in this circular building with multi storeys. The ground floor is usually the kitchen hall or a sundry shop. And the upper floors are the bed rooms. They even have a well for water consumption in each house.
In the center of those clusters are the playing area, a market place and places where they rare poultry. To me this place is very unique and you don't get to see them in any other places. There are many tulous in Fujian and we only visit one of the the villages.