As was often the case with Celtic churches from this period, the church was associated with a well. It was built by the monks of Penmon and was believed to have healing powers by some people visiting it. It is probably one of the oldest buildings in Penmon. It has been said that the lower stone walls near the well were part of Seiriol’s church in the 6th century; if so, this would make it the oldest remaining Christian building in Wales. A small chamber surrounds the well. In modern times, water from the well has been used as a symbol of Anglesey by the island’s representatives at the launch ceremony of the 10th International Island Games (held in Guernsey in June 2003) and the 11th Island Games (held in the Shetland Islands in July 2005).