Cathedral of Saint Mel in Ardagh

The Cathedral of Saint Mell is the name given to the ruins of a small, Early Medieval church in the village of Ardagh, County Longford in Ireland, not to be confused with St Mel's Cathedral in the town of Longford. Church reform in the 12th century made Saint Mel's Cathedral in Ardagh the centre of the Diocese of Ardagh and Clonmacnoise, demonstrating the importance of the site as a Cathedral and bishopric see.

Source: Wikipedia — Cathedral of Saint Mel in Ardagh (CC BY-SA 4.0)