The Giant's Causeway
Around 40,000 basalt columns, a giant who never existed, and a Spanish Armada shipwreck: the Causeway's story is wilder than its legend.
Published
Quick Facts
- Location
- North coast of County Antrim, Northern Ireland
- Formed
- Around 50 to 60 million years ago, during intense volcanic activity
- Number of columns
- Roughly 40,000 interlocking basalt columns
- Column height
- Up to about 12 metres, in the tallest sections
- Basalt layers
- Three divisions of the basalt succession, built from multiple lava flows: Lower, Middle and Upper
- Heritage status
- UNESCO World Heritage Site since 1986; National Nature Reserve
- Famous legend
- Built by the giant Finn McCool to reach Scotland
- Visitor numbers
- Over 1 million visitors a year in the years before 2020
The giant who never built it
Ask anyone in Antrim who built the Causeway and you'll hear the same name: Finn McCool, or Fionn mac Cumhaill, the legendary Irish warrior-giant. The story goes that Finn built a path across the sea to Scotland to fight his rival, the Scottish giant Benandonner. When Finn crept across for a look, he realised his enemy was far bigger than expected. He fled home, and his wife Oonagh disguised him as a baby and tucked him into a huge cradle. Benandonner arrived, saw the size of the 'baby', and reasoned that the father must be colossal. He fled back to Scotland, tearing up the causeway behind him as he went. There is a lovely twist in the geology. Matching basalt columns turn up at Staffa in Scotland, home of Fingal's Cave. The legend is not far off the mark.
Lava that cracked into perfect shapes
The real story is just as dramatic. Around 50 to 60 million years ago, this part of the world was a landscape of fissures and volcanic eruptions. Molten basalt poured across the chalk, forming a vast lava plateau. As the thick lava cooled and contracted, it cracked, rather like drying mud, but on a monumental scale. The cracks tend to form hexagons because that pattern relieves stress most efficiently. Those cracks then spread downward, leaving columns packed tightly together. Most columns have six sides, though you can find some with four, five, seven, eight and even more. Their tops form stepping stones that run down into the Atlantic. The result looks so geometric that visitors have long assumed it was carved by hand.
A scientific argument and a famous name
The Causeway came to wider attention in 1693, when the Royal Society in London heard a presentation about it. Soon, scholars were arguing over how it had formed. One camp claimed the columns were crystallised from water. Another argued that they came from volcanic fire. This was part of the great eighteenth-century dispute between Neptunists and Vulcanists, which helped shape modern geology. In 1739 the Irish artist Susanna Drury painted watercolours of the site, and they won her a prize from the Dublin Society. Engravings of her work spread across Europe, making the Causeway a celebrity long before anyone could easily visit.
Named features and a Spanish shipwreck
Many formations here have nicknames, and spotting them is half the fun. The Giant's Boot is a stone shaped like an enormous boot. The Camel is a rock that really does look like a resting camel. The Wishing Chair is a natural seat formed from columns, and the Organ is a cluster of tall columns that resemble pipes. The Spanish Armada also left its mark. In 1588 the galleass Girona was wrecked off this coast with the loss of about 1,300 lives. Only nine people are reported to have survived. A bay nearby, Port na Spaniagh, is named after the disaster. Treasure recovered from the wreck in the 1960s is now displayed at the Ulster Museum in Belfast.
What to look for when you visit
Start with the Grand Causeway, the best-known section, where the tops of the columns form a natural pavement. Then look beyond it. The cliffs behind rise in layers, with the Lower, Middle and Upper Basalts visible as bands in the rock face, each built from multiple lava flows. The Giant's Organ and the Honeycomb show the columns at their most striking. The Amphitheatre is a curved bay beneath the cliffs, and it gives a sense of the scale of the old lava flows. If you have the energy, a cliff-top path gives a very different view, looking down on the columns and out across the sea. Wear sturdy shoes: the rocks can be slippery when wet, and the Atlantic weather changes quickly. UNESCO gave the Causeway World Heritage status in 1986, and it remains one of the best-loved landmarks in the whole of the UK.
Notable people
- Finn McCool (Fionn mac Cumhaill)
- Susanna Drury
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