The old Celtic missionaries always looked for three things when setting up their cells: proximity to the sea, nearness to a town or village, and a spring. Obviously those working far inland couldn't choose the first, but the second and third were invariable.

When, in the 600s, Saint Trillo came to north Wales, he chose this spot beside the sea on which to establish his little cell, that served as both habitation and chapel. In the fourteen centuries since then the tiny stone building has withstood all that man or nature can throw at it. Until very recently, all baptisms in the parish of Rhos-on-Sea were conducted with water taken from the well in the church and regular services are conducted in the building during the summer months.