The small village of Cyffylliog lies some 6km south west of Ruthin, where the Afon Corris and the Nant Gladur stream meet the Afon Clywedog. The village itself is clustered around a small crossroads, upon which used to stand a smithy. In 1259 the village is named, ‘Kyffellauc’ and as ‘Kyffylyog’ in 1400. The name translates as, ‘the place of pollard trees or stumps.’
St Mary’s Church was actually, until 1873 a chapel of ease, attached to Llanynys, serving those who found it difficult to attend the parish church. The church itself is difficult to date, but it is said to have been built by Griffith Goch of Bachymbyd and Pentre Coch, and if so must be considered to have a late 12th century foundation. The church itself is pretty enough, though it has failed to impress architectural historians. The church was almost completely rebuilt in 1876, during which, according to an anonymous report in the ‘Archaeologia Cambrensis’ wall paintings were discovered. These were destroyed, however, during the restoration – it seems that the church was for some time unroofed and rain washed the plaster from the walls. It retains some of 13th or 14th century tracery in the east window, and both the font and what was left of the rood screen are medieval in origin. It had a sturdy wooden belfry before the 17th century, which must have been an impressive site, but of course that has long since gone.