The fact that you can visit incredible Heimaey at all is something of a miracle – because the oozing lava of the Eldfell volcano threatened to seal the harbour off completely. Fortunately, its advance was halted by gallons of seawater, pumped onto it by the plucky islanders, who saved their fishing industry in the process. Iceland's famous for its scenery, and the huge castles of volcanic rock that rise out of the sea's waves here are some of the country's most dramatic.