History
Formation of the Giant's Causeway
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What's the story?
What's the story?
How did the Giant's Causeway come to be? It is a question that has stirred debate for centuries. Now, science can help us explain this natural phenomenon.
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Lava flows
Lava flows
60 million years ago the land here was different: the climate was warmer and vegetation thrived. Tectonic plates were moving - Europe and North America were moving apart. Magma from deep inside Earth spewed through cracks in the surface. Lava flowed. It cooled in contact with air and rock, hardening into basalt.
See fissure eruption in Hawaii, March 2011
© US Geological Survey
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Creating columns
Creating columns
For hundreds of thousands of years, all was relatively quiet. Then the earth cracked open again and more lava forced its way out. This time, the lava cooled slowly and evenly in a deep pool. Cracks travelled through the cooling rock, creating the columns we see stretching up...
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Honeycomb effect
Honeycomb effect
...and making the honeycomb pattern we can see today. There are over 40,000 columns at the Giant's Causeway, most are six-sided, but there are others with fewer or more sides. Later eruptions left these columns hidden deep underground.
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Exposure
Exposure
It took millions of years of erosion for the columns to begin to be revealed. The sea level rose and fell and rose again. It wasn’t until after the last ice age, about 15,000 years ago, that the columns were revealed at the shore as they are today.
© Andrea Hirt
What's the story?
Lava flows
Creating columns
Honeycomb effect
ExposureLegend
Legend has it that the giant Finn McCool fashioned the Giant's Causeway so he could walk across the sea to Scotland and face Benandonner, his great rival.
Spanish wreck
Port na Spaniagh, Spaniard Rock and the Spanish Organ are a few features at the Giant's Causeway. But what's the story behind these names?
Maritime heritage
The National Trust is refurbishing a century-old racing skiff to bring back the local maritime past.