Cathedral church of St Deiniol

The nave has a 6-bay, 2-order arcade carried on octagonal piers and square bases; linked hoodmoulds. Above this the stone walls are rendered. Oak roof with bosses, crenellated tie beams and stone corbels. Modern inner porches to N and S; slightly off centre 3-order tower arch with steps leading up to a further modern inner porch. Square pulpit with chamfered corners and panelled reliefs; C15 octagonal font on modern platform and with modern canopy. Heavily moulded crossing arches with half-round responds to W; choir screen of 1908 by Oldrid Scott and rood of 1950 by Alban Caroe. The chancel has encaustic tile floor and canopied choir stalls; 5-bay timber lierne roof by Scott. Low blocked doorway to N beside a Netherlandish C17 wood carved statue in blocked window opening; reredos of 1881 by Oldrid Scott. 3-bay hammerbeam roofs to Transepts; S transept serves as the Lady Chapel and has painting (1934) by Brian Thomas set into the former arched opening to the medieval Lady Chapel; a tomb recess in the S wall traditionally contains the body of Owain Gwynedd but it is later than that and seems to relate to the resiting of the body. Two broken medieval stone crucifixes, one to the tomb recess and one to the reredos. Collection of medieval stone carved pieces gathered at the NW end including the well detailed C14 monument to Eva. The Mostyn Christ hangs at the W end of the N arcade, a Bound Rood said to be dated 1518 and possibly from Rhuddlan Priory. Many C19 wall monuments. Three windows have glass by David Evans of Shrewsbury originally made in 1838 for the E window; moved in 1873. S Transept window made in 1885 by Mayer of Munich and present E window by Clayton and Bell (1873).

Rubble masonry with some dressed stone; mainly lead roofs and crenellated parapets to nave and tower. Diagonal buttresses to bell tower and stepped buttresses to nave with niches to N side; Scott's gabled buttresses with detached shafts to chancel.

2-bay chancel, transepts, crossing tower, 7-bay nave and west tower. 5-light mullion and transom E window. One 5-light ogee traceried window to S side and 2 smaller C16 windows over the buttress and blocked window remains of the Romanesque church; on the E wall of the S transept beside this is the blocked former chapel opening. The N side has paired and single lancets to vestry with Gothic chimney stacks. The central tower has 2 carved roundels to each face, at W over 4 lancets. The transept gable ends have plate tracery windows, with dog tooth ornament to N. 3-light nave windows with reticulated tracery to aisles; only 6-bays of the clerestory are glazed. Rainwater heads are dated 1791. Blind ogee headed niche over the low SW entrance with 4-order roll and sunk chamfer mouldings, boarded doors and strapwork hinges; similar to N side entrance. 4-stage W tower with stringcourse set offs, crenellated parapet and crocketed finials; clock faces to N & S sides over 3-light belfry openings. 3-light W window with ogee and tear drop tracery; the inscription below reads "Thomas Skevington Episcopus Bangorie Hoc Campaniele et Ecclesiamfieri fecit Ao Partus Virginei - 1532". Square headed W entrance with label and similar boarded doors.