A battlement in defensive construction, such as that of city walls or castles, consists of a parapet (i.e., a protective low wall between chest-height and head-height) with openings or indentations at intervals to allow the discharge of arrows or other projectiles from within the structure. These openings may be closed by metal grates when there is no danger of attack. The word comes from French bataillon, which means "small flag." In military contexts, a battlement is one of several small eminences projecting from a wall or rampart, each provided with its own guard tower or casement. In medieval castles, the term referred to the elevated walkway along which soldiers could fire their crossbows down into the courtyard. They would stand on stools or move aside when an arrow was fired. Today, the term more commonly refers to the raised area above a doorframe or window where pots of flowers or plants might be placed.