Aerial photograph of St Dwynwen's Church, Llanddwyn Island.
St Dwynwen's is a ruined church on the small craggy isle of Llanddwyn. This was a cruciform church and it shows only early sixteenth century architectural detail. The southern part of a rounded churchyard is depicted on the OS County series 1st edition, on which its northern part appears to have been displaced by later fields or enclosures. The church consists of a relatively short nave, trancepts and a relatively large chancel. The walls are of stone rubble with sandstone dressings. With the exception of a plinth on a fragment of the nave walling, the only detail preserved belongs to the chancel. Here the east and south windows are preserved, but lack their tracery. The stair turret in the north trancept return presumably led to the rood loft. The cruciform plan is unusual in the region. The church is associated with the ruined house, traditionally that of the priest, some 50m to the south-west. Ffynnon Dowynwen was located nearby.
The feast of St. Dwynwen was is held on 25th January and is the Welsh equivalent of St Valentine's Day.