If an Irishman tells you that Finn McCool built the Giants Causeway so two feuding giants could settle their differences, check for a twinkle in his eyes, for perhaps he has been telling you a folk tale. Volcanic activity 60 million years ago created these rugged, symmetrical rock formations, seemingly steppingstones that lead into mists and legend. In 1693, Sir Richard Bulkeley, a fellow at Trinity College in Dublin, presented a paper on this “natural curiosity” near Bushmills in County Antrim, Northern Ireland. The arguing began: Was this made by men with picks? Was this nature’s handiwork? Did a giant place these steppingstones? It wasn’t until 1771 that the origin of the causeway was put down to volcanic activity. Or was it?