These rocks are a geological mystery. They are not part of this coastline at Dunraven but imported from further down the Brisol Channel. The theory is that the great flood of 1607 was caused by a tsunami as a result of an earthquake off the west coast of Ireland. The flood surged inland on the Welsh and English sides of the Bristol Channel and an estimated 2000 people lost their lives. The rocks have been deposited in an arc in the bay.