Arrowslit

A narrow vertical slot cut through the curtain wall or tower face for surveillance and the discharge of projectiles. In the southern Moroccan kasbah the arrowslit is typically formed during the pisé pour by inserting a tapered timber blank into the formwork and removing it after the course has set; the surviving slot is wider on the interior face than on the exterior, providing a wide field of fire from a small external opening. By the late nineteenth century these openings were largely vestigial, retained as a symbolic and stylistic register rather than for actual military function.