Sip back as we discover Northern Ireland and explore the rugged, windswept intertidal shores of County Antrim’s mythical Giants Causeway. This is one of the most iconic natural landmarks in the world to visit with over 40,000 distinctive hexagonal interlocking basalt columns formed by a volcanic eruption between 50 - 60 million years ago at the start of the Palaeogene Period. Designated as the UNESCO Giant’s Causeway and Causeway Coast World Heritage Site in 1986 this 4Km stretch of the northern County Antrim is managed by the National Trust.
County Antrim is a captivating destination especially if you are travelling the Causeway Coastal Route between Belfast and the historic walled City of Derry~Londonderry. The county offers stunning natural beauty, historical landmarks, vibrant culture and great craic. If you are planning a visit to the Giants Causeway you may wish to also take in several other impressive sights and experiences.
Maybe a distillery and tasting tour at the Bushmills the world's oldest licensed whiskey distillery dating back over 400 year and whose water is drawn from the River Bush that flows over the area’s basalt rock; book an experience to walk the 30-meter Carrick-a-Rede rope bridge originally used by salmon fisherman or visit the medieval fortress of Dunluce Castle once inhabited by both the feuding McQuillan and MacDonnell clans. Then again how could you pass up the the opportunity to play the "Giants Grave" a Par 5 on the challenging Dunluce Links Course at the Royal Portrush Golf Club.
The Giant's Causeway is steeped in both scientific intrigue with more than a pinch of local folklore. The Irish mythical tale of the Causeway involves a legendary giant Celtic warrior named Fionn Mac Cumhail or Finn MacCool. He was the leader of the Irish warriors known as the Fianna and he is believed to have either created the Causeway as a bridge to Scotland to challenge his rival called Benandonner as part of a long running feud. Conversely, according to an 1830 poem he built the Causeway for love having fallen in love with a Scottish lass and was sad that he couldn’t reach her. This alternative story appears not to take into account that Finn MacCool was at the time married to a formidable woman called Oonagh who would eventually outwit Benandonner to save Finn MacCool.
The Giants Causeway was first accurately interpreted by Rev. Dr Hamilton in 1786 as a sequence of volcanic lava flows. It is today generally accepted that the Giant's Causeway forms part of the western extent of the British and Irish Igneous Provence formed at the beginning of the Palaeogene Period during an interval of 43 million years between 66 - 23 million years ago when the North American Tectonic Plate and Eurasian Tectonic Plate of continental Laurasia began to breakup and the North Atlantic Ocean began to open up.
The area of the Giants Causeway lays along a line of crustal weakness where massive outpourings of basaltic lava vented and flowed out over a landscape of Cretaceous Period Ulster White Limestone in successive layers covering large areas of what is now Northern Ireland.
The basalt cooled and solidified to form a thick plateau part of the larger Antrim Lava Group that spans across much of the region. There are three main basaltic sequences of the Lower, Middle, and Upper Basalt Formations. Following the vent of the initial lava there was then a hiatus where a quiescent period of little volcanic activity. During this time the lava was weathered and eroded producing layers of reddish rock rich in iron and aluminium known as the Interbasaltic Formation upon which a hilly forest landscape developed.
Then volcanic activity resumed again and massive outpourings of ocean floor lava began to flow through pipes and fissures into the valley of the Causeway pooling the upper tholeiitic basalt up to 90 meters in thickness.
This lava lake of molten basalt cooled relatively quickly, uniformly and as it contracted it also fractured. These conditions were ideal for the phenomena of columnar jointing to happen forming a pavement of thousands of hexagonal columns. The fractures typically followed a hexagonal pattern because the structural integrity of a hexagon shape can distribute stress evenly because the 120-degree angles make it mechanically stable for the efficient and balanced release of surface tension in each direction during contraction.
While hexagons are the dominant shape of many columns the Giants Causeway also has a variety of other geometric alternatives with some columns having four, five, seven, and even eight sides. The Giant’s Causeway basalt columns are iconic but not unique and can be seen at a number of other locations around the world including the Cascade du Ray-Pic waterfalls in the Ardeche of France.
The Giant's Causeway features an estimated 40,000 interlocking basalt columns that descend from the cliffs and out to sea. These columns vary in height and diameter with most between 30 and 40 centimetres wide and reaching heights of up to 12 meters.
The distinctive appearance of the Giant's Causeway today is the result of millions of years of weathering and erosion. During the Ice Ages, glaciers scoured the landscape, stripping away softer rock layers and exposing the basalt columns. Following the retreat of the ice, the pounding waves of the Atlantic Ocean further eroded the cliffs and columns revealing their geometric forms. The natural sculpting of these columns has leant themselves to attract names such as Wishing Chair, The Camel, The Organ, Giant's Gate and the Giant's Loom that some say was used by Finn for weaving.