Giant's Causeway

Some 40,000 basalt columns step down from the cliff foot into the sea on the north coast of County Antrim, most of them six-sided, some with as few as four or as many as eight sides, the tallest about 12 metres high. They formed around 50 to 60 million years ago, when very fluid lava poured through fissures in the chalk and pooled in thick sheets. As each sheet cooled slowly it contracted and cracked, the way drying mud does, and the cracks ran downward to split the rock into near-regular prisms; horizontal fractures then divided the columns into stacked segments, often with a concave top and a convex base. The regularity looks engineered, which is exactly what made the place famous. In the eighteenth century the Dublin artist Susanna Drury's views of the causeway were engraved and published across Europe, and the caption to one such plate in the French Encyclopédie carried Nicolas Desmarest's early suggestion that columns like these were volcanic in origin.

Local tradition, of course, has a different explanation. In the best-known version, the giant Fionn mac Cumhaill built the causeway across the North Channel to fight the Scottish giant Benandonner, then took fright at his rival's size; his wife dressed Fionn as a baby, and Benandonner, imagining the size of the father of such an infant, fled home and tore up the road behind him. The same basalt surfaces again at Fingal's Cave on the Scottish island of Staffa, which may have fed the story. Many of the rock features along the shore carry names from it, such as the Giant's Boot, the Organ, the Chimney Stacks and the Camel's Hump.

The causeway and the surrounding coast were made a UNESCO World Heritage Site in 1986, and most of it is owned and managed by the National Trust. The stones themselves are free to walk to; the paid visitor centre, opened in 2012 after its predecessor burned down in 2000, bundles parking, exhibitions and guided walks. The National Trust marks four trails of between roughly 0.8 and 2 miles, including a fully accessible route, and the Causeway Coast Way continues for 33 miles along some of the finest coastline in Ireland.

Getting there

The site is on the B147, about 2 miles from Bushmills and 15.5 km from Coleraine. The nearest airport by distance, Islay (ILY), is across the sea in Scotland and of no practical use; City of Derry Airport (LDY) is about 47 km away and Belfast International (BFS) about 68 km. By public transport, take the train from Belfast or Derry/Londonderry to Coleraine and change to Ulsterbus service 172; the seasonal Causeway Rambler (402) also serves the coast, and there is a park-and-ride from Bushmills.