Eglwys Cwyfan

Twice daily, the tide cuts this ancient church off from the mainland completely, creating one of Wales' most atmospheric ruins. Known as the 'church in the sea', Eglwys Cwyfan sits on tiny Cribinau island, accessible only at low tide via a rocky causeway that disappears beneath the waves.

Built in the 12th century, the stone walls still stand remarkably intact despite centuries of salt spray and storms. What remains is just the shell - roofless now, with grass growing where the altar once stood. The setting is absolutely spectacular, especially when approached on foot from the Aberffraw road as the sea comes into view.

Timing is everything here. Check tide times before you go, or you'll find yourself stranded for six hours or more. The walk across takes about ten minutes over slippery rocks, so decent shoes are essential. Families with young children might struggle with the uneven terrain.

Photography enthusiasts will love this place - the contrast between medieval stonework and crashing waves is properly dramatic. It's free to visit and worth combining with nearby Aberffraw beach for a proper day out. From Silver Bay Holiday Park or other sites around Ty Croes, it's an easy drive to this remarkable survivor of Welsh ecclesiastical history.