How were the Cliffs of Moher formed?

1the cliffs

The Cliffs of Moher, on Ireland's west coast, are almost 400 million years in the making — let's see how stone became sky-high wall.

2ancient delta

Three hundred twenty million years ago, this spot wasn't cliffs at all — it was a river delta, dumping sand and mud into a shallow sea.

3layered rock

Layer after layer, season after season, sand and mud piled up and pressed into rock — that's why the cliff face shows stripes.

4uplift

Over deep time, Earth's crust pushed these layers upward, lifting the old seabed high above the waves — that's called uplift.

5wave erosion

Then the Atlantic Ocean took over, smashing waves against the base year after year, chewing away softer rock and leaving the hard layers standing tall.

6today

Today the cliffs stand over 200 metres tall in places — a slice of ancient riverbed, lifted up and carved by the sea, still eroding a little every year.