Garderobe

He splashed some tepid water on his face from the basin beside his bed and took his time squatting in the garderobe, the night air cold on his bare skin.

In the early medieval period (1066-1300), the solution in huge stone castles was garderobes: small rooms that jutted out over the walls with a hole covered by a seat. Castle builders tried to site garderobes over a stream or a moat, but this was not always possible.

Even with the seat, most garderobes in castles did not encourage long stays.[…]Despite the unappealing and unsanitary nature of garderobe shafts, besieging forces on more than one occasion successfully entered castles by having men climb up the shafts.