Nanna's Cave

Nanna’s Cave is a natural sea cave on the north-east coast of Caldey Island, Pembrokeshire. It sits high above today’s high-tide line, facing open water. The cave’s rectangular mouth is about three metres wide and three and a half metres tall. Inside it extends roughly five metres before narrowing. The floor is uneven limestone, worn smooth by thousands of years of feet. Archaeologists believe the cave was first used more than ten thousand years ago. When the land bridge to the mainland still existed, hunters gathered here. Excavations have uncovered stone tools from the Mesolithic period and bones of extinct animals. Human remains from the Creswellian and early Neolithic have been dated, making these some of the oldest securely dated skeletons in southern Britain. Nearby Potter’s Cave and Daylight Rock show similar layers, while Eel Point on the west coast reveals a different diet. Visitors reach the cave by a cliff-top path from the island’s monastery. Inside, the air is cool and still, lit only by natural light from the entrance. The walls bear faint traces of ancient fires and tool-work. Outside, the view stretches across Carmarthen Bay to the distant Gower coast. The cave’s name comes from the Norse goddess Nanna, linking the site to older traditions.