Bishops Gate, 42 Mussenden Road, Downhill, Castlerock, Co. Londonderry, BT51 4RP

Bishops Gate, Downhill Estate — Triumphal Arch, Gate Lodge and Bridge, c.1785

This is a free-standing triumphal stone arch with an attached two-bay single-storey stone gate lodge, built around 1783–1785 to designs by Michael Shanahan, who was also responsible for the Bishop's Palace, the Mussenden Temple, and the Lion Gate Lodge elsewhere on the Downhill Estate. Originally known as the 'Coleraine Gate' or the 'Coleraine Battalion Arch', it was built to commemorate the Coleraine Battalion of the Volunteers. The structure faces south, with the lodge set at a right angle to the east, and sits on the north side of Mussenden Road as the easternmost entrance to the Downhill Estate. It appears uncaptioned on the first edition Ordnance Survey map of 1831 and was listed in 1976; the gate lodge was renovated in the mid-1990s.

The Arch

The triumphal entrance screen is built in sandstone ashlar in the Doric order. Its centrepiece is a round-headed arch with a fluted archivolt rising from dentilled and fluted impost mouldings, supported on a pair of flat-panelled, squat pilasters with paterae to the plain spandrels. The arch is flanked by a pair of engaged Doric columns with fluted necks, which carry an architrave and frieze decorated with bucrania (carved ox skulls) and bishop's mitre carvings, with a plain framed tablet at the centre. Above this rises a full pediment with mutules and a carved coat of arms to the tympanum. The heraldry is deliberate: the plaque on the front of the pediment bears an ounce (the heraldic term for a leopard or lynx) surmounted by an earl's coronet, reflecting the Earl Bishop's secular title, while the plaque on the rear pediment is surmounted by a bishop's mitre, reflecting his ecclesiastical one.

Flanking the pedimented arch are lower screen walls in channel-rusticated sandstone ashlar, each with a responding flat-panelled squat pilaster to its inner end supporting a dentilled and fluted frieze with paterae. Each screen wall is finished with a raised parapet decorated with bell-flower garlands, paterae and guilloche trim. The western screen wall contains a blind niche — once occupied by a figure of Diana the Huntress, which by the end of the 19th century had been moved to a niche on a landing inside the Castle — while the eastern screen wall has an arched pedestrian entrance. The arch carries a pair of replacement wrought-iron gates, and the pedestrian entrance has an arched double-leaf timber door with raised-and-fielded panels.

The north elevation of the pedimented arch is detailed in the same manner as the south, with a fluted frieze and a further coat of arms to the tympanum, while the screen walls on this side are built in coursed rubble basalt, with a voussoired arch to the pedestrian entrance.

The style has been assessed as late Adam in character, and the treatment of the arch is ultimately derived from Roman models such as the Colosseum. While the triumphal arch follows a standard late 18th-century pattern-book type, the quality of the stonework on both the arch and lodge reflects the ambitions of the Earl Bishop. Carving and stone cutting were carried out by James McBlain, whose son David McBlain continued the family tradition; the father and son were responsible for much of the carved work at Downhill.

The Gate Lodge

The gate lodge is rectangular in plan, set at a right angle to the triumphal arch, with the east screen wall abutting the centre of its front (west) elevation. Its hipped natural slate roof has rolled lead ridges and sits behind a lead-lined sandstone ashlar parapet wall with a cavetto moulded cornice below. A central sandstone ashlar chimneystack with vermiculated quoins carries a single octagonal clay pot. Cast-iron guttering on drive-through brackets and a timber fascia serve the north and east elevations, with cast-iron downpipes.

The west and south elevations are faced in sandstone ashlar with a plain plinth course, while the north and east elevations are in uncoursed rubble basalt. Each corner is finished with a cluster of colonettes rising to the cornice line and surmounted by sandstone pinnacles on diminutive pedestals. Window openings are round-headed with vermiculated voussoirs, quoined surrounds and flush vermiculated sills, fitted with replacement multi-pane timber sash windows with ogee horns.

The principal west elevation is four windows wide: two blind windows to the north end, and to the south end three openings with a pointed-headed door opening set between the windows. The door opening is flanked by clustered colonettes on plinth blocks with a matching arched surround, and carries a replacement hardwood panelled door. The door opens onto a stone platform with five stone steps. The north side elevation is single-bay with a round-headed window opening with a voussoired basalt head and a replacement timber casement window. The south side elevation is two windows wide and detailed as per the front elevation, with a rendered wall abutting the east corner to enclose the rear garden.

Abutting the south end of the rear elevation is a single-bay, single-storey-over-basement rendered extension with a hipped natural slate roof and timber casement windows with concrete sills, built around 1970.

The lodge's pointed-headed door opening introduces a nod to fashionable 'gothick' taste that is not repeated elsewhere on the estate — a juxtaposition of styles described by one authority as 'most satisfying'. The lodge is thought to have been built in 1784, shortly after the gateway itself, and is also attributed to James McBlain, with work resembling that attributed to him at Hillsborough Castle. It is listed in the Townland Valuation at £2 10s. In the 1880s the gate lodges were recorded separately from the main house, and the lodge, valued at £2, was for some years the residence of the McConaghy family. After the death of the original gatekeeper Robert McConaghy, his widow remained in the house into her seventies, working initially as a seamstress before retiring, as recorded in the 1901 and 1911 census returns.

The Bridge

To the west of the arch is a bridge that allowed access between the two sides of the park and carried the former Coleraine Road before it was realigned. The bridge is constructed from coursed rubble with rock-faced voussoirs and quoins, and its soffit is lined with brick. The parapets are a mixture of sandstone blocks and in-situ concrete.

Setting and Approach

The arch and lodge sit on the north side of Mussenden Road at a level lower than the road itself, accessed via a short slip road. Sharing this slip road are the Downhill outbuildings to the east and the kennel keeper's house to the north. A bitmac drive descends from the slip road, enclosed by a retaining wall to the west built in vermiculated sandstone ashlar, and continues through landscaped gardens on the north side of the arch to provide public access to the Downhill Estate.

The Bishop's Gate stands at the head of a long driveway designed to play with views of the Castle as it is approached: the house is visible in the distance, then hidden, then revealed again from a different angle, with the driveway leading — in the Georgian manner — to the rear stable courtyard rather than the principal elevation. It was constructed as a second entrance to the Downhill demesne, following the building of the Lion Gate around 1780, and together with the broader group of structures on the estate it forms a significant picturesque composition.