Hakka Dwellings of China

The Hakka people of China were originally immigrants from the northern regions who moved and settled into the southern provinces. Because they were latecomers to the area, the Hakka had to set up homes in mountainous regions and were often subject to attack. This led them to develop a unique form of architecture and buildings that they called tu lou, or earthern structures.

Focussed on defensive purposes and consisting of one entrance and no windows at ground level, these communal structures would serve as a fortress and apartment building in one. Round in shape, they were internally divided into many different compartments for food storage, living quarters, ancestral temple, armoury etc and the larger houses would cover over 400,000 square feet in size and house 500-600 people.

Wikipedia: Hakka architecture web page.

Hakka House Architecture web page at AsiaWind.com.