St Mary's Church, Tal-y-llyn is a medieval church near Aberffraw in Anglesey, north Wales. It was originally a chapel of ease for the parish church of St Peulan's, Llanbeulan, but the township that it once served, Tal-y-llyn, no longer exists. It was declared a redundant church in the early 1990s, and has been in the care of the Friends of Friendless Churches since 1999. Services are held once per month during part of the year. The date of the church is unknown, but the oldest parts could be from the 12th century. The chancel was rebuilt in the 16th century, and a side chapel added in the 17th century. The church furnishings, such as pews, pulpit and communion rails, were added in the 18th century, although some of the pews are modern replacements after vandalism. It is a Grade I listed building, a national designation given to buildings of "exceptional, usually national, interest", because it is "a very rare example of a virtually unrestored Medieval church of simple, rustic character." History and location St Mary's Church is in a rural and thinly populated part of Anglesey, about northeast of Aberffraw and about southwest of Gwalchmai. It stands on a low mound with a circumference of approximately ; the wall around the churchyard, which contains no gravestones, follows the shape of the mound to some extent. Its original purpose was to serve as one of five chapels of ease for the local parish church, St Peulan's, Llanbeulan, about to the north; St Peulan's itself has now closed. The township that St Mary's served, Tal-y-llyn, has now disappeared, although before the time of the Black Death there were 22 houses here. The date of foundation of the church is unknown. The nave is the oldest part of the church, possibly built in the 12th century. Later changes saw the rebuilding of the chancel (in the late 16th century) and the addition of a chapel on the south side of the building (in the 17th century). It was used for services until the early 1990s, and was then made a redundant church in about 1992. It was placed in the care of the Friends of Friendless Churches in 1999, who hold a 999-year lease effective from 19 November 1999. Services are held in the church on one Sunday afternoon per month between May and October. Architecture and fittings The church was constructed using