Beuno founded his church in Clynnog Fawr in 616. This was a clas church which is a combination of a monastery and college in one: a place of prayer, ministry, missionary work and education.

The church lies on the North Wales Pilgrim route, making it a notable milestone on the way to the destination of Bardsey Island, the alleged burial place of 20,000 saints. Clynnog was also a destination for pilgrimage, with pilgrims in search of healing. It was believed that immersing in the nearby well and sleeping overnight on Beuno’s grave, could heal from threatening diseases such as rickets or epilepsy, especially among children.