4a Old Coastguard Cottages, North Street, Ballycastle, Co Antrim, BT54 6BZ

This is a former watch tower built in the medieval revivalist style, designed by E.T. Owen (assistant architect in the Irish Board of Public Works, Dublin) under the direction of his brother J.H. Owen (the board's principal architect). It was constructed in 1868 as part of a Coast Guard Station that originally comprised five houses and a tower. The station was vacated by the coastguard around the 1960s and the buildings subsequently reverted to the Trustees of the Fullerton Estate.

The watch tower is a three-storey rectangular structure built of local pinkish sandstone, roughly coursed. It is positioned off-centre within a terrace of coastguard cottages and breaks the building line at both front and rear. The flat roof is topped with a high brick-built parapet wall with a sandstone band circumscribing its base. Projecting from the parapet wall are machicolations supported on two large pointed sandstone corbels. The parapet is pierced on all sides, including the projections, with narrow gun loops. A conical stairwell top is visible above the parapet, giving access to the roof.

The south-east elevation features a central ground floor double hung sliding sash window (boarded up), a similar 12-pane window directly above at first floor level, and a quasi-segmental headed double hung sliding sash 9-pane window at second floor. Blank slits flank the windows on each side, and the corner arrises are chamfered. The north-west wall is similar, except the ground floor has a narrow door with fanlight and the first floor has a pair of double hung sliding sash 8-pane windows. Two large downpipes from trunkheads drain the flat roof. Narrow gun loops also decorate the projecting side walls.

The tower has much architectural and historical interest and possesses group value with the adjoining former coastguard houses in the terrace. The building was undergoing renovation at the time of survey under a scheme with listed building consent, including internal alterations and modification of the parapet wall.