Famous for its role as a Vishnuite temple during the twelfth and thirteenth centuries, Angkor Wat's subsequent fate has attracted less interest. Traces of modifications to the outer walls of the complex may, however, hold the key to understanding its role during its later phases. Here, holes in the masonry and structural changes to the substantial walls are investigated to demonstrate how wooden structures with a defensive role were built to protect the site sometime between the late thirteenth and early seventeenth centuries. The results reveal how Angkor Wat may have made its last attempt at defence.