Peel Castle quarry

Folded rocks at Peel castle quarry

The old quarry outside the northern wall of Peel Castle contains thick beds of sediment originally deposited as flat layers on the sea bed. These beds have now been folded into arch-shaped anticlines and trough-shaped synclines by the massive forces of the Caledonian mountain-building episode when Laurentia collided with Gondwana 410 million years ago.