Terrace, Shane's Castle Park, Antrim, Co Antrim

A long masonry-built battery and deep vaulted terrace at Shane's Castle Park, surrounded on three sides by a parapet with embrasures for 21 cannons. The main front faces south.

The structure is built of regularly coursed basalt, inclining from the ground to a sandstone cordon under the parapet at an angle of about 80 degrees, with sandstone dressings and more finely worked basalt above the cordon. At the right-hand extremity of the south front stands a circular tower with a semi-circular arched sally-port and a narrow rectangular slit opening to the base on the east side, with another narrow rectangular slit opening facing to the rear. The tower projects well above terrace level, topped with a projecting crenellated parapet carried on mock machicolations. A small central turret rises from its centre with similar crenellations and mock machicolations, surmounted by a tall flagpole. Narrow Gothic arched openings face each side of the turret.

At the left-hand extremity of the south front is a diagonally placed square bastion with three faces rising above terrace level to projecting battlements on mock machicolations. The front face contains a semi-circular arched opening at terrace level containing a cannon, with a small rectangular opening at ground level in the battered base and a narrow rectangular slit opening at higher level in the left-hand wall of the base.

Each of the shorter sides of the battery and terrace, facing approximately east and west, contains one segmental arched opening high up in the base, temporarily closed with loose iron bars near the south end, and a triangular bastion at the north end. The triangular end bastions rise above terrace level to projecting crenellations on mock machicolations. The one terminating the west wall contains a semi-circular arched opening in the parapet facing inland and a narrow rectangular opening at ground level in the base facing toward the water. The corresponding bastion to the east wall has blank faces.

On the terrace, the inner faces of parapets are of similar walling to the exterior. The square and angled bastions are open, with similar walling to the exterior except crenellations flush with no machicolations. Twin semi-circular arched openings serve the circular tower, with alternating red brick and sandstone block reveals. The tower contains basalt rubble inner walls with stone spiral steps descending to the sally-port and modern open tread timber stairs spiralling up around the central turret to a wooden boarded floor providing a viewing platform at parapet level.

The terrace surface comprises coarse gravel of crushed stones in the main south front area, with the rear return areas at each end grassed and bordered by gravel along the perimeter parapet. Around the entire perimeter at each embrasure stands an 18th-century iron 12-pounder naval cannon supported by an upright leg formed by what appears to be a hollow stoneware coping tile on end.

The terrace is supported entirely on an extensive system of brick arched vaults, mainly of segmental form but with some semi-circular form. Under the main terrace along the south front runs a double row of 26 barrel vaults separated by a long groin-vaulted corridor extending from the western to the eastern side of the battery, where segmental arched openings appear in the end or side walls. Under the northern portion of each side return of the main south terrace are batteries of tunnel vaults running in an east-to-west direction—three at the west end and four at the east end—with arched openings facing into open courtyards.

In the east courtyard, basalt rubble walling facing west contains four segmental arched open doorways with sandstone ashlar voussoirs and sandstone block dressings to jambs, with a short return facing north containing one similar doorway. In the west courtyard, similar walling facing east contains three such doorways, the walling rising above basement storey height to boundary walling which abuts the Camellia House.

Almost the entire area of basement vaulting supporting the terrace is in darkness except in the immediate vicinity of the arched openings from the courtyards and at the two openings at each end of the long corridor and the low opening in the diagonal bastion, which are deep within the structure and difficult of access. The double row of vaults under the main south-front area of the terrace is reached by four routes: open doorways in each of the two end courts on the north side; the circular vaulted basement lobby at the south end of the old castle; and a passage off the transverse corridor to the south of the tall pillared and vaulted kitchen which forms part of the rear return of the early 19th-century castle-style additions to Shane's Castle.

The building stands in a very rural area within the demesne of Shane's Castle, close to the shore of Lough Neagh, which formerly came up to and around the base of the building. With the later lowering of the lough level, the water has now receded, leaving a flat area of grass in front of the terrace. To the rear of the terrace stand the ruins of the old Shane's Castle, while on part of the terrace itself stand the unfinished remains of later additions to the castle, including the conservatory known as the Camellia House, which is the only completed portion.