terreplein

Terre-plein, from French meaning “earth flat,” is a term used in fortification and landscape architecture to denote a flat earthen platform or terrace. It describes a level area formed by earth within or on top of a structure, serving as a base for other features or as a working surface.

In military architecture, the terre-plein is the earthwork on which elements such as a parapet sit. It forms a raised, earthen platform behind or within a rampart, providing support for the parapet and space for gun crews and artillery emplacements. The terre-plein helps absorb impact and can protect troops by elevating firing positions relative to the surrounding terrain. Its presence and dimensions vary with historical period and fortress design, particularly in trace italienne (star fort) systems where earthworks are integrated with stone regiments.

In landscape and civil architecture, terre-plein refers to a raised, level terrace shaped by earth. It is used to create flat areas on sloped ground, to provide access and circulation, or to support planting and views. Such terraces are common in terraced gardens, hillside developments, and historic courtyards where a level surface is needed on uneven terrain.

See also: parapet, rampart, glacis, terrace, earthwork.