Tulou, or earthen buildings, are a special type of rural dwelling unique to the Hakka people living in the mountainous areas of southeast China's Fujian Province. Tulou are commonly rectangular or circular in shape and built like enclosed fortresses with thick load-bearing rammed earth walls. They range in height from three to five stories and can house hundreds of people who live together in one cohesive community. This unique form of architecture creates well-lit, well-ventilated, earthquake-proof and windproof buildings that reflect the wisdom and creativity of the Hakka people. With many of Fujian's tulou listed as UNESCO World Heritage Sites, these buildings are not only exceptional expressions of a unique form of architectural heritage, but also showcase the harmonious relationship between man and nature.