Yett

A yett (from the Old English and Scots language word for "gate") is a gate or grille of latticed wrought iron bars used for defensive purposes in castles and tower houses. Unlike a portcullis, which is raised and lowered vertically using mechanical means, yetts are hinged in the manner of a traditional gate or door, and secured by bolts attached to the yett, or by long bars drawn out from the wall or gateway.