About sixty million years ago, lava poured across what is now the Antrim coast, and as it cooled, it cracked into columns, most of them hexagonal, tens of thousands of them, packed together like a vast honeycomb. That, in short, is the Giant's Causeway, and the science is simple enough, though the sight is still strange. The columns rise in steps from the sea, some forty or fifty centimetres across, with tops as flat as tabletops, forming a causeway that disappears into the waves. It was named a UNESCO World Heritage Site in 1986.
The legend is better. According to Irish tradition, the giant Finn McCool built the causeway as a path to Scotland so that he could fight his rival Benandonner, but when he saw how big the Scottish giant was, he ran home and disguised himself as a baby. Benandonner took one look at the size of the baby and fled in terror, tearing up the causeway behind him. Identical columns exist at Fingal's Cave on the Scottish island of Staffa, which gives the tale a certain geological logic.
Another piece of history lies offshore. In 1588, the Spanish Armada galleass Girona, carrying hundreds of survivors from other wrecked ships, was driven onto rocks near here, and nearly all aboard died. Treasure from the wreck, found in the 1960s, is now in the Ulster Museum in Belfast. A small cove nearby is called Port na Spaniagh in memory of the disaster.
For the rider, the Causeway is the crowning stop of the coastal route. The A2 from Ballycastle and the B146 and B15 near Bushmills wind along the coast with big views and good surfaces, though summer traffic is heavy and the narrow lanes near the site are congested. The visitor centre, run by the National Trust, has a large car park, and the walk down to the stones takes about fifteen minutes, with a shuttle bus for those who prefer not to walk. Boots are better than bike boots on the wet rocks. Spring and autumn are the best times for fewer crowds and dramatic skies, and the weather is as changeable as ever.
Bushmills, a few kilometres away, is the home of the oldest licensed distillery in Ireland, with a licence dated 1608, and tours and tastings are available. Portrush, about ten kilometres to the west, is the nearest sizeable town with fuel, supermarkets and seaside amusements. A bowl of seafood chowder with soda bread at a café in Bushmills is the standard lunch.