The Hakka fort is a largely unique Hakka-style residence. It's not only praised as a wonder in the architectural history by architects, but also intoxicated by historians, folklore experts, poets, artists and normal tourists. Gannan Hakka forts, totally over 500 existing, are distributed in Longnan, Quannan and Dingnan (all over the three counties), southern Xinfeng, southern Anyuan and some places of Xunwu, among which Longnan is the one with most Hakka forts concentrated. Most of them are square, showing different style to the round Tulou in western Fujian and Weilongwu (square inside and round outside) in eastern Guangdong. The materials used for Hakka architecture can either be brick, stone, or rammed earth. The external wall is typically 0.8--1.5 meters in thickness and the entire building could be two to four stories in height. Often turrets were also built on the top floor to extend the range of defensive power. There is always a superscription of Fort ** on the head of the gate, such as Fort Pan'an, Fort Yanyi, Fort Longguang, etc. The gate was usually reinforced with stone and covered with iron. There must be at least one well in a fort to supply water. In order to withstand a protracted siege, a Hakka fort often also had their own sophisticated sewage systems in four different directions, such as Fort Yanyi in Longnan.
What's more, the kinds of compound residence like 'Three Up Three Down" (two-floor house with three main rooms each floor), 'Nine Wells Eighteen Halls", etc are also of great features. Good examples are the folk houses in Bailu Ganxian and the 'Ninety-nine And A Half" in Shicheng.