Years ago, the Irish giant Fionn mac Cumhaill was challenged to a fight by his rival the Scottish giant Benandonner. However the two were separated by the North Channel, and no matter how much the other tried neither could cross the water. So anxious was Fionn to brawl against Benandonner he built an enormous causeway across the channel to the Scottish side. Fionn defeated his rival in the clash, but Benandonner, frightened Fionn might follow him, destroyed the causeway as he retreated back to Scotland.
Or so the legend goes, anyway. Geologic study asserts the Giant’s Causeway in the Republic of Ireland was formed when volcanic activity around the region of Antrim caused highly fluid molten basalt to push through chalk beds and form an extensive lava plateau, the contraction of the basalt caused it to take the shape of spindly pillars.
Looking at the basalt columns in reality, I preferred the giant story.