Portaferry Castle is a small tower house in built in the 16th century by William Le Savage. In 1635, Patrick Savage's brother-in-law, Sir James Montgomery of Rosemount (Greyabbey), repaired the castle by roofing and flooring it so that his sister could live in greater comfort there.
It is a square building with a small projecting turret on the south corner. It is three storeys high plus attic and there is no vault. Most of the eastern corner is in ruins. The entrance at the base of the tower is protected by a small machicolation and the entrance to the ground floor chamber is protected by a murder-hole. A curved stairway within the tower rises to the first floor and a spiral stairway in the west corner continues to roof level.
References:The Broch of Gurness is an Iron Age broch village. Settlement here began sometime between 500 and 200 BC. At the centre of the settlement is a stone tower or broch, which once probably reached a height of around 10 metres. Its interior is divided into sections by upright slabs. The tower features two skins of drystone walls, with stone-floored galleries in between. These are accessed by steps. Stone ledges suggest that there was once an upper storey with a timber floor. The roof would have been thatched, surrounded by a wall walk linked by stairs to the ground floor. The broch features two hearths and a subterranean stone cistern with steps leading down into it. It is thought to have some religious significance, relating to an Iron Age cult of the underground.
The remains of the central tower are up to 3.6 metres high, and the stone walls are up to 4.1 metres thick.