Abergavenny Gate House.

The information board on the left says that the building is a typical barbican gatehouse. A barbican was a wall or tower which protected a castle gate from attack. When Abergavenny Castle was built, the gate was a simple opening in the curtain wall. Unusual door features suggest that the gatehouse was added in the early years of the 15th century. At this time, the last Welsh War of Independence was being fought under the leadership of Owain Glyndŵr.

The gatehouse may have been built following an order from King Henry IV to improve the castle defences after an uprising in 1403 against William Beauchamp, Lord of Abergavenny.
In addition to the drawbridge, the gatehouse had accommodation on the first floor, probably for the Constable who controlled the castle when Lord Abergavenny was elsewhere. The room had a fireplace, large windows and access to the wall walkways, and contained the winch for the drawbridge.