Patrick visited ‘the Well of Findmagh’, also called 'Slán' or ‘the Healer’, near Manulla.
The pagans and their wizards venerated it as a god, the King of the Waters, and made immolations to its deity.
The well was square and a square shaped stone closed the mouth of the well, but the water kept spilling from the joints of the stones.
Also they believed that a dead prophet was buried under this stone, making for him a shrine, so that the water might wash his bones because, in life, he feared fire and adored water.
Patrick, in aim to convert the pagans, asked them to raise up the stone and see what was under it, but they were unable to do so. Patrick and Cainnech exorcised and blessed the stone; then Patrick, stretching out his hands, lift it off the top and placed it on the ground. Nothing was found beneath the stone, so the pagans believed in God.
The church founded there became the principal church in the region and the well was later re-named St Patrick's Well. Patrick left Cainnech to rule over it.