St Llwchaiarn's Church, a re-built medieval church, is situated within a polygonal churchyard, whose east and south boundaries are curvilinear. The north churchyard boundary is delineated by a road. A spring, depicted on historic (1905) Ordnance Survey mapping, is sited at the roadside, some 160m west of the churchyard. A stream runs under the road at this point and continues east, delineating the southern churchyard boundary before joining the Afon Ystwyth, which forms the west churchyard boundary. The church is located some 350m south of Castell Tan-y-Bwlch (the original castle at Aberystwyth), which was constructed in 1110. This and the original church may have been contemporary. St Hychan's Church was not a parish church during the medieval period, but was a chapelry belonging to the rectory of Llanbadarn Fawr in the Deanery of Ultra-Aeron and the parishioners of Llanbadarn Fawr still contributed towards the repair of the church in the nineteenth century. The church had become a parish church by 1833.

The church's small, octagonal font bowl and stem are thought to be thirteenth-fourteenth century in date, and with graffito of 1630. The pre-1878 church is thought to have consisted of nave and chancel and porch. In 1833 the porch was noted to be a good example of Early English architecture. By 1878 the church is thought to have lost its medieval character. It had a tall, narrow, tapering bellcote with two-centred opening. The porch also had a two-centred opening and the east window, dating from the eighteenth-early nineteenth century, was a semicircular headed single light. The south wall had segmental, square windows and there was a western gallery entered via an external flight of steps leading a doorway in the west wall. There was a vestry in the angle between the porch south wall and the nave west wall.

The rebuild of 1878, although on the foundations of its predecessor, retained nothing from the earlier fabric. The present church was built to designs of Archibald Richie, and is constructed of rubble stone with yellow Oolite dressings. It consists of three-bayed nave and chancel under a single roof, west bellcote, gabled north-west porch and lean-to north-east vestry with small organ chamber; and plate tracery windows, each window different on the south side. The porch was extended to the west around 1921 in order to provide an organ chamber. The vestry and organ chamber were renovated in 1958. Stained glass includes work, in the east window, by Heaton, Butler & Bayne (1879).

Sources include:
Cambria Archaeology, 2000, Ceredigion Churches, gazetteer, 48.
T.Lloyd, J.Orbach & R.Scourfield, Buildings of Wales: Carmarthenshire and Ceredigion (2006), p.539-40.

N Vousden, RCAHMW, 10 March