A "fossé" is a French term that translates to "ditch" or "trench" in English. It typically refers to a long, narrow excavation in the ground, often used for drainage or to mark boundaries. Fossés can be found in various landscapes, including agricultural fields and urban areas, serving practical purposes in managing water flow and preventing erosion. In historical contexts, fossés were often used as defensive structures around castles or fortifications. These ditches would be filled with water or left dry to create obstacles for potential attackers. The design of a fossé can vary, but its primary function remains consistent: to provide protection and manage land use effectively.