Plas Celynin is situated about quarter of a mile north east of the small village of Llangelynnin, which is approximately two miles south west of Conwy. The house is a Grade II listed 'rectangular two-storey Regency house of circa 1810, apparently built as the rectory for Llangelynin (new) church' (NPRN 43711). The principal building material is stone rubble, although 'the main front is rendered, under a shallow-pitched, hipped slate roof with wide eaves.' The symmetrical main front of the house is orientated to the west, and the projecting central bay has a 'central ground-floor timber bay window, canted and with a lead roof.' The southern entrance to the house is deeply recessed and arched, 'with contemporary 6-panelled door within.' A 'contemporary service projection to the rear, or east side of the house, has been latterly extended to give a gabled rear wing; complete with '12- and 15-pane windows and modern French door.' The house has been further extended to the north-east, with a single-storey lean-to.' Plas Celynin was described by CADW at the time of its inspection in September 1995 as 'an elegant Regency villa in a commanding position which retains much of its external character.'
In 2018, Gwynedd Archaeological Trust discovered a previously unrecorded well on the eastern side of the property.
Sources: CADW database of listed building, reference number: 17709 and an archaeological mitigation report of Plas Celynin by Gwynedd Archaeological Trust, published in August 2018 (project no. G2568 and report no. 1437)
M. Ryder, RCAHMW, 10th April 2019