Murder holes — Middle Ages

The story behind the answer

These are vertical openings in the ceilings of gate passages that let defenders attack enemies directly below—dropping stones, scalding water, heated sand, or shooting downward—while staying protected. They are inside the gateway, unlike machicolations, which project along the outside of walls, and unlike arrow slits and embrasures, which are openings in walls or battlements for shooting outward, not straight down.

They formed part of a castle’s “killing zone,” often between successive portcullises in a gatehouse or barbican. If attackers forced the outer doors, defenders could trap them beneath these apertures and rain attacks from above. Common from the 13th century onward, they’re preserved in many European castles and illustrate how medieval fortification favored layered, vertical defense over mere thick walls.