The contribution intends to provide a reading and an in-depth study of the defensive heritage located in the Zhujiang river basin and its delta in Guangdong, China. The paper focuses on the case of diaolou, defensive towers already listed as UNESCO since 2007, built from the sixteenth century until the first half of the twentieth century in Kaiping country. These buildings show an interesting mixture of some local models and typologies and specific characters and styles borrowed from western examples.

The research takes as a privileged point of view the relationships that these settlement systems forge with the hydrographic resource, which generates a territorial groove that determines the morphology of the territory and constitutes a historical vehicle of crossings. The arrangement of the fortified towers with respect to the river line is influenced by centripetal and centrifugal actions aimed at responding to defensive needs in the geography of this territory.

The heritage of the diaolou seems to respond to two types of defensive demands: one linked to historical facts and the frequent bandit raids that took place in the Guangdong area in the nineteenth century; the other connected to geographical and hydraulic data, as the protection from the phenomenon of inundation and the consequent placement of the towers in the floodplain of the Zhujiang river. The course of the river gets in shape through the architectural technique, in the construction of towers and defensive works and, in the same way, some aspects of the design of this territory are defined through the description of the forms of the river.

Architecture, hydraulic engineering and geography work together in defining the form of the settlement and invest the scale of the buildings, generating specific architectural types and morphological characters suitable for responding to the problem of water control, conservation and distribution.