What did they throw down murder holes?

In medieval castles, "murder holes" were openings in the ceilings of entrances or passageways where defenders could drop or throw various projectiles onto attackers below. Common items thrown down included boiling water, hot oil, rocks, or other heavy objects to injure or deter enemies attempting to breach the fortress. This tactic was part of the broader defensive measures employed to protect the castle and its inhabitants from intruders.