The Giant’s Causeway is an area of basalt columns along 6 kilometers (4 miles) of the northern coast of Northern Ireland.
It is located in County Antrim, about 5 kilometers (about 3 miles) northeast of the town of Bushmills.
Geological studies of these formations over the last 300 years have greatly contributed to the development of the earth sciences, and show that this striking landscape was caused by volcanic activity during the Tertiary, some 50–60 million years ago.
There are approximately 40,000 of these stone pillars, each typically with five to seven irregular sides, jutting out of the cliff faces as if they were steps creeping into the sea.
Most of the stone pillars are hexagonal, although there are also some with four, five, seven or eight sides.
Stone pillars vary from 38 to 51 centimeters (15 to 20 inches) in diameter and measure up to 25 meters (82 feet) in height. They are arrayed along cliffs averaging some 100 meters (330 feet) in elevation.
Some of the structures in the area, having been subject to several million years of weathering, resemble objects, such as the Organ and Giant’s Boot structures. Other features include many reddish, weathered low columns known as Giant’s Eyes, created by the displacement of basalt boulders; the Shepherd’s Steps; the Honeycomb; the Giant’s Harp; the Chimney Stacks; the Giant’s Gate and the Camel’s Hump.
The discovery of the Giant’s Causeway is attributed to the Bishop of Derry who had visited the site in 1692.
The existence of the site was announced to the wider world the following year by the presentation of a paper to the Royal Society from Sir Richard Bulkeley, a fellow of Trinity College, Dublin.
The site first became popular with tourists during the nineteenth century, particularly after the opening of the Giant’s Causeway Tramway, and only after the National Trust took over its care in the 1960s were some of the vestiges of commercialism removed.
The Giant’s Causeway was declared a World Heritage Site by UNESCO in 1986.
It was also declared a national nature reserve in 1987 by the Department of the Environment for Northern Ireland.
Today, the Giant’s Causeway is owned and managed by the National Trust and is one of the most popular tourist attractions in Northern Ireland.
The area is a haven for seabirds such as fulmar, petrel, cormorant, shag, redshank, guillemot and razorbill, while the weathered rock formations host a number of plants including sea spleenwort, hare’s-foot trefoil, vernal squill, sea fescue and frog orchid.
The dramatic sight has inspired legends of giants striding over the sea to Scotland.
Deriving its name from local folklore, it is fabled to be the work of giants, particularly of Finn MacCumhaill (MacCool), who built it as part of a causeway to the Scottish island of Staffa (which has similar rock formations) for motives of either love or war.