Giant's Causeway, Northern Ireland, UK

 It is easy to see what this magnificent natural formation is a UNESCO World Heritage Site. It has inspired and sustained legends and while there are similar formations (like Fingal's Cave on Scottish isle Staffa on the other side of the sea), it is unique. At most 12 meters high and around 28 meters thick in the widest places, they were formed during a volcanic eruption during the Paleogene period 50-60 million years ago as the lava cooled near the limestone forming a similar structure to dried, cracked mud. However, the stones just form part of a 3800 square kilometer area including the surrounding 100m cliffs, which form the largest remaining lava plateau in Europe.

Part of the Antrim peninsula in Northern Ireland, people have been visiting as tourists since the 1693 'discovery' by the Royal Society. It was a popular feature on The Grand Tour as well, popularized by Miss Susana Drury's paintings.