St Gredifael's Church, Penmynydd, is a little altered Medieval rural church. The chancel and nave date from around 1400, while the north chapel and south porch were added early in the fifteenth century. The church is constructed of limestone and grit rubble with grit dressings and a slate roof. The windows are original, comprising single, two or three trefoiled lights in either a two-centred head or quare-frame. The sixteenth century arch-braced truss roof has been repaired.

The late fourteenth century alabaster tomb chest of Gronw Fychan and his wife Myfanwy is located in the north chapel of the church. Gronw Fychan was the great-uncle of Owain Tudor and ancestor of the later Tudor families in Anglesey. The tomb is made from alabaster, and is probably from the sculpture workshops of Derbyshire or Nottinghamshire. There are five shields on each side and two on each end, those on the sides hung in cusped panels alternating with canopied niches for statues of equal width, those on the ends hung in two-light panels. He is very robust and clothed in armour with a surcoat, with his head in chain-mail and his moustaches spread on top of it. His feet are on a lion. Myfanwy has more delicately detailed clothing and ornaments, her head in a wimple embraced by two winged angels, her feet under a hem where two lapdogs also nestle.

Sources include:
Cadw list description 2002
Site file notes; Anglesey Inventory, 1937 [1960 reprint], p. 129.
Haslam, Orbach and Voelcker (2009), The Buildings of Wales: Gwynedd. Pevsner Architectural Guide, page 209.
Richard Suggett, Painted Temples: Wallpaintings and Rood-screens in Welsh Churches, 1200–1800, (RCAHMW 2021).

RCAHMW 2022