A tulou is an earthen roundhouse found in the Fujian province of southeastern China. Tulous were built between the 12th and 20th centuries to house large clans of the Hakka tribe.

There are thousands of tulous all over the Fujian countryside.

An entire clan - up to 800 people - lived in a tulou, which functioned like a small city.

Each tulou is several stories high and is built around an inner courtyard. Tulous have tiled roofs and wide eaves that hang over their sides.

Tulous were designed with defense in mind. A tulou has only one entrance and there are no windows on the ground floor. This design was supposed to keep bandits out.

Principles of Feng Shui influenced a tulou's design and its placement in the mountainous countryside.

A tulou is divided vertically, so that a family occupies two or three rooms on each floor.

While the outside of a tulou is plain looking, the interior is elaborately decorated.

46 tulous in the southwestern part of Fujian province have been designated UNESCO World Heritage Sites.

The largest of these tulous is Chengqilou. It has more than 400 rooms and once housed more than 600 people. Today, about about 300 people live here; many people have given up the community afforded by the tulou in exchange for life in the big city.