Giant's Causeway

Giant's Causeway is Northern Ireland's first UNESCO World Heritage Site: more than 40,000 interlocking basalt columns, formed by cooling lava around 60 million years ago and, in legend, laid by the giant Finn McCool as a road to Scotland. The stones themselves are free to walk on; the Visitor Experience ticket adds the on-site car park, an hourly guided tour with the storytelling team, an audio guide in 11 languages and an exhibition, and an electric shuttle bus runs down to the shore. Four waymarked trails cover the 5km site, including a fully accessible clifftop route, and dogs on leads are welcome everywhere, tours included. Reviewers rate the audio guide and the exhibition's 3D map of the coast, and many book the guided clifftop hike. Tips from visitors: pre-book, since parking nearby is scarce and the main car park is reserved for ticket holders and members, or use the park and ride from Bushmills; and arrive early, because the stones are crowded by late morning even in May.