Ystradgynlais is a town in the county of Powys, Wales and sits just south of the Brecon Beacons National Park. The river Tawe runs through the town from its source in the Old Red Sandstone hills before flowing into the Bristol Channel in Swansea.
St Cynog's Church can be found on the eastern bank of the Tawe. Originally a Norman church serving the town, St Clywedog's was rebuilt in 1861, 50m south of the old church, which is now marked with an obelisk. The style of St Clywedog's is Victorian Gothic, with ornate detail on the windows and a scissor truss roof inside. An organ and vestry were added to the church in 1933.