Answer: Basalt Columns

Located along the coast of Northern Ireland in County Antrim, you’ll find one of the largest, and likely the best known, examples of basalt columns in the world. There, stretching along the coast near the town of Bushmills, is an exposed geological formation comprised of approximately 40,000 interlocking columns. The area is known as The Giant’s Causeway due to the local legend that claims the columns are the remains of an enormous causeway crafted by one giant to go battle another giant.

In reality, the columns were formed around 50-60 million years ago when intense volcanic activity in the region forced huge volumes of highly fluidic molten basalt up through the region’s chalk beds, creating a vast lava plateau. The molten basalt cooled and contracted (much like mud in a desert cracking apart) into the columnar structures seen in the photo here.

The location is a designated World Heritage Site and considered one of the greatest natural wonders found in the United Kingdom.