St Mary's Roman Catholic Church, Grove Road, Craigavole, Garvagh, Co. Londonderry

St Mary's Roman Catholic Church is a free-standing gabled blackstone church with an engaged square bell tower, dated 1855 and situated on the west side of Grove Road in the townland of Craigavole, south of Garvagh. This is a modest but well-executed example of mid-Victorian Gothic Revival architecture, built as a replacement for an earlier chapel of 1734. The church replaced even earlier worship spaces—a fort or rath in the same townland, followed by the simple thatched structure erected in 1734. The current building appears on the second edition Ordnance Survey map of 1853 as an "RC Chapel" under construction. The architect remains unknown.

The church has a rectangular plan with a square tower and sacristy (added later) to the west. The walls are constructed of squared blackstone built to courses with flush pointing, featuring sandstone dressings and quoins. The pitched natural slate roof carries blue and black angled ridge tiles, leaded in part and to the gable, with stone verges and a metal cross-finial. Cast-iron half-round rainwater goods are fitted to projecting boxed eaves. Roughcast render appears on the west gable.

The east-facing gabled front presents the principal elevation, with two interlocking Y-tracery multi-pane lancet windows flanking a central pointed-headed entrance. The entrance comprises a replacement double-leaf timber-sheeted door with a fixed timber-sheeted tympanum, all set within a chamfered sandstone surround with blackstone voussoirs. Above the windows sits a pierced quatrefoil at the apex of the gable. Below this, a slate datestone bears a Latin inscription reading "IN GLORIUM DEI. / SUB B.Y.MARLE PATROCINIO/ H/ED EDDLESIA edificala esl/ ANNO DOMINI MDCCCLV / REV D AD M S A OTERSON. P.P"—commemorating the building's dedication in 1855.

The lancet windows throughout feature multi-paned timber casements in chamfered ashlar sandstone surrounds with chamfered sills and blackstone voussoirs. The south elevation displays five evenly spaced lancets. The north elevation mirrors the south.

The engaged square bell-tower stands at the centre of the west gable and is flanked by an M-profile sacristy with an undercroft. The tower has a parapet with pierced quatrefoils and crocketted corner pinnacles, with a sandstone drip mould marking the transition between stages. The belfry stage contains a pointed-headed louvered opening with hood mould on all four sides, while the first stage has a narrow pointed-headed blind opening and, on the west face, a multi-paned Y-tracery window. The sacristy, built in two visible stages, opens to the north via a modern timber-sheeted door accessed by two concrete steps. A louvered timber-sheeted door serves an adjoining store-room, beside a double-Y-tracery timber casement window. A similar window appears on the south elevation. The M-profile gable features a modern timber casement window in the left bay; steps descend to a modern timber door with metal vent panel providing access to the undercroft at the right bay.

The church retains much of its original character despite some alterations and refurbishments. Basalt forms the primary building stone, with Barony Glen sandstone used at the upper reaches of the tower. The building has not altered in plan form since construction.

The church was listed in 1977, with the extent of listing encompassing the church building, walling, and gate pillars. The new "RC Chapel and yard" appears in Griffith's Valuation of 1856–64, valued at £15 and 5 shillings for the yard. A revaluation in the early 1930s set the figure at £60, and a plan from the valuer's notes shows the nave with tower, vestry, and store to the west.

Historically, the Worshipful Company of Mercers, on whose estates the church stands, contributed financially to the building fund, as they did for other Catholic and Presbyterian churches in the area. Donations were also extended to Catholic and Presbyterian clergy on the estates, provided they ministered to the Company's tenants. Prior to the construction of the new church, the Mercers had regularly funded the re-thatching and repair of the old chapel.

The setting comprises a mature rectangular plot accessed via a narrow tarmacadamed road that terminates at an adjoining farm entrance. Eight concrete steps with modern metal handrails lead to the front entrance. A small graveyard lies to the southeast of the site, featuring headstones dating from the mid-nineteenth century. The plot is lawned on three sides and bounded by mature trees and hedges. The eastern boundary at the road is marked by a modern timber fence. Roughcast-rendered curved entrance walls flank the front approach, terminating in square piers that support modern "Northburn Steel" gates. A large tarmacadamed car park occupies the northern side of the plot.