High Quality Content by WIKIPEDIA articles! St Mary`s Church, Llanfair-yng-Nghornwy is a medieval parish church in the north-west of Anglesey, north Wales. The date of foundation of the church, which is in the village of Llanfair-yng-Nghornwy, is unknown, but the oldest parts date from the 11th or 12th century. It has twice been enlarged: in the 15th century, when the chancel was rebuilt, and in the 16th century, when a chapel was added to the south of the chancel, separated by three arches. The tower at the west end is from the 17th century. A south porch of unknown date has been converted into a vestry, and the church is now entered through the tower.