21 Boleran Park, Garvagh, Coleraine, Co. Londonderry, BT51 5EJ

21 Boleran Park is a single-storey vernacular house with attached outbuilding, built before 1830, located down a lane off the west side of Boleran Park in open farmland. The house is of architectural importance as a relatively intact and rare survivor of a vernacular dwelling, and the group of buildings as a whole is of historic significance as a clachan settlement.

The house has a rectangular plan with a direct entry layout and three bays. The roof is pitched with fibre cement slate and three rendered chimneys with half-round metal gutters. The walls are lime-washed lime render. Window and door openings are square-headed. The windows are timber sashes with 2/2 glazing and projecting masonry cills. The entrance door is a replacement timber sheeted door; the outbuilding door is planked.

The front east elevation displays four windows and two doors arranged with symmetry between the central and right bay, where the entrance door sits with a window on each side. The southern two windows are positioned closer together within the left bay, and the outbuilding door is located to the south. The south elevation is abutted by an outbuilding. The rear west elevation has three windows and two blocked doors. The north elevation is abutted by an outbuilding slightly set back from the east frontage.

The house is surrounded by outbuildings both attached and detached. An attached outbuilding stands to the north (no. 1) and another to the south (no. 6). Three further detached outbuildings are arranged around the farmyard (nos. 2, 3, and 4), with one located to the south (no. 5). All outbuildings are single-storey with lime-washed random rubble walls. Roofing varies: nos. 1, 3, 6 and part of 5 have corrugated metal sheeting, while the remainder are finished with natural slate and fibre cement slate to no. 5. The windows to no. 5 are metal-framed. Doors throughout are assorted replacements.

A clachan (cluster settlement) is shown on the first edition Ordnance Survey map of 1832 at this location, with some buildings surviving to the present day. The group does not appear in the Townland Valuation, as the dwellings were of a simple vernacular type below the valuation threshold. The second edition Ordnance Survey map of 1849–53 captions the group "Upper Boleran" and depicts it surrounded by tree planting. Griffith's Valuation (1856–64) records the clachan as divided into four holdings: a house and offices to the south valued at 15 shillings and leased by John Dempsey; a house and offices centrally located leased by Bernard O'Connell and valued at £1; a house to the north-east leased by John O'Connell and valued at £1 15 shillings; and one to the south-east leased by Reverend John McLoughlin, likely the priest of the nearby Roman Catholic chapel, valued at £2 10 shillings.

The occupancy history shows considerable change over subsequent decades. The 1901 census records four inhabited dwellings, three of which were thatched. Thomas Doherty occupied the most substantial house—the one valued at £2 10 shillings with four rooms and not thatched—living there with his son, daughter-in-law and two young grandsons. Catherine Atkinson lived in a three-room thatched house with her son, daughter and a farm servant. William J O'Connell occupied a two-room thatched house with his sister Maggie, a seamstress, and Mary Connell, a widow of 60, lived alone in the remaining two-room thatched house. By 1910, Catherine Atkinson's son Thomas had taken over another dwelling on the site, and by 1925 a third, leaving William J O'Connell in the remaining house. Valuer's notes from the 1930s, 1940s and 1950s record that the buildings—three of which remained thatched and comprised a kitchen and one or two rooms—gradually fell out of domestic use and were converted to agricultural outbuildings.