Traditions and Hearthside Stories of West Cornwall, Vol. 2, by William Bottrell, , at sacred-texts.com
In St. Levan Churchyard is a cloven rock called St. Levan's stone. For some reason, now unknown, this must have been a venerated object when the church was built, or it would have been used in the building. The common notion, however, is that long before St. Levan's time this rock was regarded as sacred, because Merlin prophecied—
It is stated that Merlin came here with King Arthur, when he slaughtered the Danes at the battle of Velan-drùchar. The separation of this prophetic stone is so slow that there appears to be no danger of the world's ending just yet.