St Lasir's Church, Marble Arch Road, Wheathill, Co Fermanagh

St Lasir's Church is a small rural Roman Catholic church constructed in 1874 on Marble Arch Road, 4 miles southwest of Belcoo in County Fermanagh. It replaced an earlier thatched mass house that stood on the same site, built by Reverend James Cleary, Parish Priest of Killesher from 1866 to 1875. The church's authorship is uncertain, though its overall simplicity suggests it was built by a competent builder rather than a professional architect.

The church is rectangular on plan with a chancel and sacristy. It has a double-pitch natural slate roof with the entrance gable facing southeast. The walls are smooth rendered and painted, with a small projecting plinth. The southeast entrance gable features a double boarded door set within a central pointed arch, flanked by lancet windows. Above the door is a stone shield inscribed "ERECTED BY REV J CLEARY P.P. 1874". The gable has simple stone skews topped with a wrought iron cross. The windows are notably fine, with small diamond-patterned cast iron frames and margined panes set in painted stone sills.

The southwest elevation contains four lancet windows with matching cast iron windows. The northwest gable is blind but has a chancel attached with blind side walls and a large pointed arch window containing a painted timber window with intersecting glazing bars. The northeast elevation mirrors the southwest with four lancet windows. Both nave and chancel gables have raised stone skews. A projecting sacristy with double-pitched roof wraps around the junction of the nave and chancel, with a 6-pane by 6-pane painted timber sliding sash window on its northwest elevation.

The building appears substantially unchanged from its original 1874 design, though several internal alterations have been carried out. The present confessional and fireplace in the vestry date to approximately 1900–1910. The chancel contains a stained glass window by Clokey of Belfast from 1944, donated by the Gilmurray family. The Stations of the Cross are modern replacements for the original framed images, and the altar, designed by Michael Donnelly and made by O'Hara's of Sligo, dates to after 1965. Repairs in 1938 by architects James Donnelly & Sons of Enniskillen may have entailed other changes, though the extent of these is unclear.

The setting is rural and expansive, with extensive views across farmland to distant hills on all sides. The church grounds are accessed from Marble Arch Road through modern wrought iron gates supported on square rendered pillars with original painted stone pyramidal caps. The boundary to the road has modern steel railings set on rendered walling between regularly spaced rendered columns. Within the grounds stands a freestanding steel bell-tower, 6 metres high, constructed from steel angle sections bolted together and sitting on a raised concrete podium. The bell itself is dated 1896 and came from Holywell Church at Belcoo, presented to the congregation in 1931. The bell-tower itself was erected sometime after 1931 and first appears on the Ordnance Survey map of 1991.

Also within the grounds, accessed through the same entrance gates, is a late 1960s or 1970s sexton's house—2 storeys high with unpainted cement render, fibre cement roof covering, and uPVC windows and door. To the northeast, set close to the church, is a large single-storey corrugated iron shed belonging to the house. The church site is divided from the house by a low modern timber fence. A narrow tarmac path surrounds the church; otherwise the site is grassed. To the rear of the chancel is a random rubble stone boundary wall separating the church grounds from a small stream that runs under Marble Arch Road.

The original mass house predating the 1874 church is likely to have been built in the late 1700s. It is shown on the 1835 Ordnance Survey map as a rectangular block and is described in contemporary OS Memoirs as a "thatched structure more like a long barn than anything else", able to accommodate about 800 persons standing. The 1836 valuation records its dimensions as 86 feet by 23 feet by 10 feet, with two smaller accompanying structures: a thatched sexton's dwelling of 23 by 13 by 6 feet and a stable of 14 by 12 by 6 feet, located along the roadside immediately south of the mass house. These were demolished at some point prior to 1857. The 1906 Ordnance Survey map shows a small building to the north of the present church and another to the west, the former possibly a residence for the sexton.

The church is important to the local community and represents a simple church type at the core of rural life in Fermanagh, though such buildings may become less common due to falling congregations and more centralised worship centres.