Travel Northern Ireland is a land of giants, ghosts and dragons. On the north Antrim coast, you will find the Giant’s Causeway, a rocky outcrop of 40,000 hexagonal basalt columns reaching into the Irish Sea. Joan, our guide from the National Trust, explained its ancient origins. It was, she said, created by the Irish giant Finn McCool. He built it to reach his giant neighbour, Benandonner, with whom he had a score to settle and who lived over the way in Scotland, darkly visible in the distance. McCool was big (judging by the fossilised shoe he left on the beach). But Benandonner was bigger. And when McCool clapped eyes on his rival, he decided the tête-à-tête could wait and hurried home. But Benandonner followed. So, McCool pretended to be out…