The fate of drowned cities in northwest Europe

The ancient stories of fighting a losing battle against the sea are concentrated along the coast of Brittany, the Channel Islands, Cornwall and Wales.

• In Britanny, the city of Ys was said to be protected by a series of sea defences that required gates to open at low tide. Then the King Gradlon's daughter, Dahut, opened the gates at high tide, letting the ocean destroy the city.
• A similar story is told about the fate of another city in Cardigan Bay.

The lesson we can learn is that sea-level rise cannot be stopped easily.