Black Glen Lodge Cottage, Tunnel Brae, Castlerock, Co. Londonderry, BT51 4RH

Black Glen Lodge Cottage is a detached stone former gate lodge built around 1875, located at the north-easternmost entrance to the Downhill Estate near Castlerock. It is one of only two surviving gate lodges from an original five, and is Grade B2 listed.

The building is a symmetrical two-bay single-storey structure with an attic, standing on a T-shaped plan and facing north. It has a central entrance porch and a lean-to rear extension. The pitched natural slate roof is finished with roll-moulded black clay ridge tiles and has a central stone and brick chimneystack with an octagonal clay pot. Cast-iron guttering is supported on timber fascia with sheeted overhanging eaves and exposed rafter feet; cast-iron downpipes drain the roof.

The walling is constructed of random coursed rock-faced basalt, with tooled quoins. Window openings are square-headed with stop-chamfered painted masonry lintels and painted stone sills; they contain replacement 2/2 timber sash windows. The front north elevation is two windows wide with a central square-headed door opening. The door is lintel-matched to the windows and opens into a catslide canopy supported on a stop-chamfered timber frame rising from low basalt walls with concrete coping. The east gable contains a single attic-level window opening, while the west gable has a pair of attic windows. The rear elevation is abutted by a central extension with a catslide slate roof; the extension has gauged brick flat-arched window openings and cement-rendered walls with a sheeted timber door to the east.

The lodge sits at right angles to a pair of tall basalt gate piers with stacked coping, which support replacement iron gates. The site is enclosed to the north and east by tall rubblestone walls with stacked coping. A pedestrian entrance to the south pier and a further pedestrian gate to the north boundary wall provide public access to the estate via gravel driveway.

The building was constructed during the time of Sir Henry Hervey Bruce, third Baronet of Downhill, who had acquired major landholdings in the area in 1871 and took a keen interest in developing Castlerock and rebuilding Downhill Castle following a serious fire. The lodge first appears on the third edition Ordnance Survey map of 1904 and entered valuation records around 1875 at £2 5s. It was built to provide accommodation for the land steward of the Bruce estates.

The first recorded occupier was Henry Light, followed by William Lyons in 1883, who served as land steward to the Bruce family. According to the 1901 census, Lyons lived with his wife and mother-in-law, both of whom worked as domestics; the four-room house was designated second class. By 1911, William Davis had taken over as land steward, residing in the house with his wife and five children. William Carson became occupant in 1925, and by the 1930s the house remained inhabited rent-free as a gate lodge. The original ground floor comprised a reception, kitchen and scullery, with three bedrooms on the first floor.

The building was listed in 1977 and is now in the ownership of the National Trust. Renovations took place during the 1980s and 1990s, and a rear extension was added in more recent years. The lodge forms an important part of the Downhill Demesne and exhibits architectural detailing consistent with other buildings within the demesne and Castlerock village, demonstrating group value with the other listed structures in the area.