Giant's Causeway

The Giant's Causeway is a area of 40,000 basalt columns resulting from a volcanic eruption 60 million years ago. It is the only World Heritage Site in Ireland and is located on the North Antrim Coast[?] of Northern Ireland.

While recent scientific research¹ suggests the columns were formed as a natural consequence of lava cooling, legend has it that the giant Finn McCool built the causeway to walk to Scotland without having to get his feet wet.

More on geology/formation, legends

References

¹ Jagla, E. A., Rojo, A. G. Sequential fragmentation: the origin of columnar quasihexagonal patterns. Physical Review E, 65, 026203, (2002)