of the nave has two bays; it is slightly wider than the nave. The nave and the chancel have external buttresses. Internally, the chancel arch dates from the 13th century. It is wide and from the floor to the top of the arch; the supporting pillars are tall. There are windows from the early 16th century in the chancel, with the large east window in Perpendicular style (in contrast to the rest of the church, which is mainly in Decorated style). It has five ogee-headed lights separated by vertical tracery, and measures at its widest point by at its tallest. Unlike most of the other windows in the church, it contains coloured glass. A smaller window in the north wall also dates from this time, and has a square frame containing two lights; a matching window was added in the 19th century in the opposite wall. The other windows in the church are from the 19th century in various designs. One window, in the north wall of the nave, has had stained glass added as a memorial to two local residents who died in the 1990s. The entrance is through a porch (probably dating from the 16th century) on the south side of the building, at the west end of the nave. At the west end of the roof, which is made of slate, there is an ornate bellcote for one bell (added by Kennedy). There are plain iron crosses on top of the porch and the chancel. Inside, the rafters and trusses of the roof are exposed. The pews and choir stalls were added in the 19th century. The nave has a brass memorial to a former Chancellor of Bangor Cathedral, William Morgan (died 1713), his wife and son. There are other memorials inside the church, including one for those from the parish who died during the First World War. The gritstone circular font, at the west end, dates from the 12th century, and has six decorative panels. It is one of a group of fonts in north-west Wales using interlace (a medieval decorative style) showing links to Irish and Norse artistic traditions; other similar fonts in Anglesey are found at St Ceinwen's, Cerrigceinwen, St Peter's, Newborough and St Beuno's, Trefdraeth. One author says that the patterns on the fonts at Llangristiolus and St Beuno's Church, Pistyll (in the nearby county of Gwynedd) seem "closely linked" to patterns on