Basaltic Pillow Lava On Llanddwyn Island, Anglesey
Sabena Jane Blackbird / Alamy Stock Photo
Image ID: DB3BK4
Part of the Pre-cambrian Gwna Group. They were formed by undersea volcanic eruptions; as the molten rock billowed out meeting the cold sea water the rock solidified producing this pillow shape.
Location: Llanddwyn Island, Newborough Warren, Anglesey, Wales, UK