Church of St Celynin

The nave and chancel are structurally undivided, separated only by a low screen, and has stone flagged floors and whitewashed walls. The C16 5-bay roof has king- and queen-post trusses, sprung from wall posts carried on rough stone and wood corbels and braced to the tie beams. Wall-posts, braces and tie beams are moulded in all of the trusses, but the 3 easternmost trusses are more richly worked. This might indicate that the original division between nave and chancel was set further W. Only the wall posts and tie of the western truss are original. The roof also has a distinctive flat ridge beam and moulded wall-plates, except in the westernmost bay. Later boarding is behind the rafters. The sanctuary has a later boarded ceiling with a decorative ridge panel. Shallow segmental-pointed recesses in the N and S chancel walls were probably originally tomb recesses.

There are fragments of 3 wall paintings, all post Reformation. In the W wall is a Memento Mori, discovered in 2003, the upper portion of which was probably lost when a W gallery was inserted. In the nave N wall is a fragmentary inscription 'yn gwneuthur', part of the second Commandment, and part of Psalm 26 in English. They were uncovered by Harold Hughes during restoration in 1917. The chancel screen is probably C18 in its present form but may be assembled from pieces of an earlier screen. The lower panels on the N side have pierced decoration and are C16, possibly from a former rood screen. The lower panels to the S side are simpler and more recent. Both sides have turned rails to the upper section, and there are central gates of similar character. The polygonal wooden pulpit, possibly also C18, is in a more refined idiom and incorporates panels with reed-moulded decoration.

The church has a remarkable, virtually complete set of benches said to date from 1823. These simple benches record the names and addresses of their occupants, and include a complete hierarchy from vicar and gentry to servants' benches against the W wall. Other fittings include the late medieval font, comprising a simple octagonal bowl on a rectangular plinth. A chandelier is dated 1843. In the N wall is a Decalogue board in Welsh with, painted on the frame, 'Robert Pughe, Wiliam ... 1796'. There are 2 memorial tablets in the E wall. A plain marble tablet commemorates Mary Thomas (d 1785). An oval tablet has a scrolled surrounded, and is surmounted by a Bible and winged cherub, but the painted inscription has worn away.

A parish church with nave and chancel under a single roof of notably wide plan, with S porch incorporating a bellcote. Of local coursed stone, roughly dressed, with distinctive large stones visible in the upper courses, particularly in the S wall. It has also been suggested that the stonework in the lower courses may be a survival from the earlier church on the site. A raised band is below the eaves in the N and S walls. The slate roof has tiled cresting, and is behind coped gables. The S porch, possibly C17, has a coped gable surmounted by a gabled bellcote that houses a single bell dated 1842. An accompanying inscription commemorates the construction of a new church in Llangelynin. The round-headed entrance has a simple projecting hood mould. In the E wall is a narrow window. Inside the porch is a corbelled stoup and pointed S doorway with a boarded door. In the S wall, the chancel has a 2-light square-headed late-medieval window, with cusped lights, sunk spandrels and a hood mould. An inserted 2-light wood-framed window is set high towards the centre of the S wall. The E wall has a simple round-headed window with splayed voussoir head and drip mould. The 3 windows in the N wall are probably C19 insertions and are simple wooden framed windows. The westermost window is immediately below the eaves. The N doorway is said to be a C19 insertion, and comprises a simple arch with voussoirs, and a boarded door with vertical ribs. There is also a blocked narrow window set very low towards the E end of the N wall. The W wall, where the ground level is lower, has a distinctive battered plinth and a single narrow round-headed window.