Wall-walk

A chemin de ronde (French, "round path"' or "patrol path"; French pronunciation: ​[ʃəmɛ̃ də ʁɔ̃d])—also called an allure, allure or, more prosaically, a wall-walk—is a raised protected walkway behind a castle battlement.

In early fortifications, high castle walls were difficult to defend from the ground. The chemin de ronde was devised as a walkway allowing defenders to patrol the tops of ramparts, protected from the outside by the battlements or a parapet, placing them in an advantageous position for shooting or dropping.

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