Holy Trinity Church is situated within a triangular churchyard which is bounded by roads on all three sides. The church and its vicarage were built in 1858 and are depicted on historic (1889) Ordnance Survey mapping. The church is situated on reclaimed land, upon which the present (lower) village of Penrhyndeudraeth was laid out in the second half of the nineteenth century. Formerly the older settlement, Upper Penrhyn (originally called Cefn Coch), belonged to the parish of Llanfihangel-y-Traethau and was served by St Michael's Church (NPRN 43894).

Sources include:
Ordnance survey, 1889, First edition 25inch
www.britishlistedbuildings.co.uk/wa-26852-parish-church-of-the-holy-trinity-penrhyn/photos

RCAHMW, April 2012