Kilclief Castle lies just north of the village by the same name, in County Down, in Northern Ireland.
Kilclief Castle was built between 1412 and 1433 as the summer residence of John Sely, Bishop of Down. It is probably the oldest datable tower-house in the region. John Sely lived here until 1443 when he was expelled and deprived of his offices for living at Kilclief Castle with a married woman.
The castle was garrisoned for the Crown by Nicholas FitzSymon and ten warders in 1601-2. In the 18th century the castle was thatched and part of a farm. More recently is was used as a farm granary.
Kilclief Castle is 4 storeys high and has 2 projecting turrets, one of which contains a spiral staircase. These projecting turrets are joined at roof level by a high machicolation arch covering a drop-hole for dropping missiles on unwelcome visitors below. This defensive arch is familiar from castle gatehouses which is why this kind of tower house is sometimes called the gatehouse type.
This is a very nice small castle tower at the shore of the entrance to Strangford Lough. It can be visited for a small fee during opening hours.