In the medieval fortification a kind of enclosed arrowslit, overhanging on brackets outside the defensive element (defensive wall, tower, etc.) adapted to its vertical, wings and front defenses, by arrowslits and machicolation. Available only from the guard walkway or defensive floor. It served to defend the underside and for that purpose it was placed at the crown of the wall, especially at its long stretches, over the gates and to fill the dead fields. Fortified machicolation boxes were made of brick, stone and timber. A similar form was also given to latrines.