What are the reasons for the emergence of Tulou-style dwellings

Due to special historical and social reasons. The Tulou-style residence is a unique architectural form created by the Hakka people in China to adapt to the migratory and difficult living environment, and the Tulou-style residence is also closely related to the Hakka people's way of life and cultural traditions. The Hakka people emphasize saving and self-sufficiency, and the design of Tulou reflects this way of life, with all the internal facilities, so the Tulou-style dwellings are created due to special historical and social reasons.