Giant’s Causeway: The Basalt Formation on the North Antrim Coast

The hexagonal columns at the Giant’s Causeway are not cut or carved. They are a product of thermal contraction physics that produces hexagonal fracturing in cooling lava as reliably as bees produce hexagonal honeycombs in wax: the same geometry arising from completely different processes. Approximately 40,000 interlocking basalt columns formed when lava flows cooled and contracted around 60 million years ago, creating the distinctive stepped formation on the north Antrim coast. The columns range from 15 to 40 centimetres across and up to 12 metres tall.

The site is a UNESCO World Heritage Site (listed 1986) and the most visited attraction in Northern Ireland. The myth that explains the formation is more appealing than the geology to many visitors: the Irish giant Finn MacCool supposedly built the causeway as a bridge to Scotland to fight a Scottish giant named Benandonner. The same formation appears at Fingal’s Cave on the Scottish island of Staffa, making this one of the tidier mythology overlaps in European folklore.

The Site

The visitor centre (2012, Heneghan Peng Architects, won the RIBA building of the year – it is genuinely good architecture, worth looking at before going down) sits at the cliff edge above the causeway. From there, it’s 1.5 kilometres down to the shore; either walk or take the shuttle bus (£3 return).

The Grand Causeway section is extremely crowded from mid-morning in peak season (June through August). Arriving before 9am makes it manageable. Beyond the Grand Causeway, the coastal path west reveals other formations: the Organ (columns that resemble organ pipes), the Giant’s Boot (a single formation that actually resembles the described shape), and the Chimney Tops. The cliff walk west to the Causeway Coastal Route viewpoints and back takes about 2 hours and is considerably quieter than the main area.

Entry: National Trust members free. Non-members around £15 adults.

The Causeway Coastal Route

The Antrim coastal road from Carrickfergus to Portstewart is one of the better road trips in the British Isles. Key stops beyond the causeway:

Carrick-a-Rede Rope Bridge (National Trust, around £12.50): a 20-metre rope bridge suspended 30 metres above the sea between mainland cliff and small island, historically used by salmon fishermen. The views from the island back to the mainland are excellent. Book ahead online.

Bushmills Distillery: the village of Bushmills, 3 kilometres inland from the causeway, has the Old Bushmills Distillery (licensed 1608, the oldest licensed whiskey distillery in the world). Tours from £10, advance booking recommended.

Dunluce Castle: a 14th-16th century MacDonnell clan castle on a sea stack 5 kilometres west of the causeway. A section of it fell into the sea in 1639 – the kitchen with the servants still in it, according to records. £5 admission.

Getting There and Staying

The causeway is 90 kilometres northwest of Belfast, about 90 minutes by road. By public transport: train from Belfast or Derry to Coleraine, then the Ulsterbus 172 “Causeway Rambler” along the coast (summer service only).

The Bushmills Inn in the village is the most characterful option: a converted 17th-century coaching inn with a whiskey bar and a good restaurant. Doubles from around £180-260. The Causeway Hotel (National Trust, directly adjacent to the visitor centre) is the most convenient but not the most interesting. For a broader base to explore the coastal route, Portrush has the widest range of accommodation and restaurants, including Ramore Wine Bar for good seafood.