Eglwys Oen Duw

Eglwys Oen Duw is an Early English style church built of snecked, rock-faced stone with lighter freestone dressings and a steep tile roof behind coped gables. The building comprises a nave with a south porch, a lower and narrower chancel, and a slender shingled tower and spire rising over the east end of the nave. The tower is topped with a swept spire surmounted by an iron cross, with louvred bell openings.

The porch, set back from the west end of the nave, is entered through a 2-centred arch with double chamfer and no capitals. Inside are double doors with iron studs and flowing strap hinges, with small lancets in the porch side walls. To the right of the porch are two lancets, followed by a third lancet in a shallow projection aligned with the tower. The chancel south wall has a double lancet followed by a single lancet. The east window consists of three stepped lancets with a sill band decorated with foliage stops. The north wall contains a single lancet and a lower gabled vestry and organ recess. The nave north wall has three lancets and a lancet in a shallow projection aligned with the tower, mirroring the south side arrangement. The west window has five stepped lancets.

The interior is faced in red brick with freestone dressings and black and yellow brick below the cornice, topped with a frieze of encaustic glazed tiles below sill level. The floor is laid with decorative and encaustic tiles, with richer examples in the chancel. The west window has a shafted rere arch. The nave roof is a 4-bay arched-braced structure. At its east end is a 2-centred arch supporting the tower, constructed on pairs of Purbeck marble shafts with stiff-leaf capitals that stand on wide corbels enriched with dog-tooth friezes. Beyond this is the chancel arch, which has two orders of chamfer with the inner order dying into the imposts. Directly beneath the tower is a narrow wooden imitation rib vault.

The chancel roof consists of closely-spaced arched braces. Its brick walls are enriched with polychrome decoration similar to the nave, except that the east wall has a gold mosaic reredos inscribed with "Alleluia". The east window has marble-shafted rere arches with stiff-leaf capitals. A trefoil-headed piscina features a hood mould, marble shafts, and a diaper infill of polished stones set diagonally.

The large, heavy square font has a stepped base and a round stem with attached shafts at the corners bearing superimposed scalloped and waterleaf capitals. The bowl is decorated with a frieze of roundels containing relief carvings of foliage and symbolic devices. Two damaged fonts from the churches at Llanfihangel Abergwesyn and Llanddewi Abergwesyn are displayed beside it.

The polygonal pulpit is constructed of wrought and cast iron on a brick and stone base, featuring a tier of fret-cut panels below a tier of cusped arches, with a brass hand rail. The choir stalls have carved foliage to the ends and open quatrefoils to the front. The communion rail has iron uprights and a wooden hand rail.

The church contains substantial stained glass. The east window, by Clayton & Bell circa 1868, displays scenes from the Life, Passion and Resurrection of Christ in early French style. Two windows in the chancel south wall date to circa 1877 by Burlison & Grylls, both dedicated to Clara Thomas and executed in late-medieval style: the southeast window shows the descent of the Holy Spirit, whilst the southwest window depicts the Adoration and Christ's baptism. An unsigned Ascension window is located in the chancel north window. The nave west window, also circa 1868 by Clayton & Bell, depicts Gospel scenes and the Communion of Saints. In the nave north wall at the east end is a scene showing the Good Shepherd commemorating Thomas family children who died in infancy in 1836 and 1838. Adjacent to it is a window of circa 1907 to Margaret Lloyd showing "Charity". At the east end of the nave south wall is a window depicting Christ with two small children, commemorating infant deaths of 1858 and 1860. The porch west side window contains glass by Anna Beasant dated 1999. The remainder of the nave glass is unattributed.