You cannot truly visit Ireland without a visit to the legendary Giant's Causeway. Volcanic activity helped Finn McCool forge this wonder of the world some 60 million years ago. The 6km of sheer cliffs rising to over 90m and forming a series of bays are spectacular.
Ireland, Giants Causeway in Northern Ireland. Check out the natural hexagonal basalt columns, which were formed during a volcano eruption 60 million years ago. The basalt columns appear on the other side of the channel as well in Scotland.