Hakka Tulou's are multi-storey earthen houses built between the 12th and 20th centuries, mainly ny the Hakka dialect group. They house up to 800 people each. Built for defence purposes, they were called "a little kingdom for the family" or "bustling small city." Tulous were usually occupied by one large family clan of several generations; some larger tulou had more than one family clan. Besides the building itself, many facilities such as water wells, ceremonial hall, bathrooms, wash rooms, and weaponry were shared property. Even the surrounding land and farmland, fruit trees etc. were shared. Each small family has its own private property, and every family branch enjoys its privacy behind closed doors.