Rhos on Sea – St Trillo’s Chapel


   The chapel at Rhos on Sea, originally called Llandrillo yn Rhos, was named after Trillo, a 6th-century saint who built his hermitage on the offshore island. It was supplied with drinking water by a spring, which probably affected the decision to build a place of retreat in this place. For centuries, this well provided water for baptisms and also had a long tradition of healing properties. For this reason, at the beginning of the 16th century, a stone chapel was built at the spring by monks from Aberconwy Abbey, perhaps erected on the foundations of an earlier small sacral building.


   The chapel was originally located on a small island, situated near the sea coast, but formed by the branches of a river estuary, which made the surrounding areas wet and swampy (Rhos in the Celtic language means swamp). It was built as a small, aisleless, rectangular building with internal dimensions of 3.6 x 1.9 meters, located near the water source. The stocky building was covered with a stone gable roof. Along its longer side, its wall was secondarily supported by massive buttresses. The entrance was located on the western side, and on the eastern and northern sides, small slits were inserted in the walls. Inside, the chapel was covered with a pointed barrel vault, perhaps built in place of an older, more primitive vault made of overlapping stone slabs.

Current state

   Today the chapel is located on the mainland, because in the early modern period the island disappeared due to lower water levels. The building has been preserved in its entirety, although it is devoid of architectural details that could be reliably dated. The two northern buttresses are probably secondary. Inside, under the altar, there is still a well of the original spring. According to popular opinions, the chapel of St. Trillo is considered the smallest chapel in Wales or Great Britain.

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Kinross J., Discovering the smallest churches in Wales, Stroud 2007.

Reid I., Rhos on Sea Heritage Walk, Colwyn Bay 2020.
The Royal Commission on The Ancient and Historical Monuments and Constructions in Wales and Monmouthshire. An Inventory of the Ancient and Historical Monuments in Wales and Monmouthshire, IV County of Denbigh, London 1914.