As the lava from the volcanic eruptions made its way towards the Atlantic Ocean it cooled, the current basalt columns were deep inside the lava flow and cooled more slowly than the basalt layers above.

Those upper layers have over the intervening millions of years been eroded leaving the stronger columnar basalts exposed at three points that make up the Giant's Causeway.

Due to the structure of the atoms the basalt has formed regular sided columns, some 40,000 of which are visible at this part of the coast. They are polygons, mostly hexagons although there are pentagons, octagons and even the occasional square.

What makes the area interesting is that the main causeway appears to drop down off the headland above the Atlantic here dipping under the waves as if to be a pavement or roadway built by a prehistoric giant.

Today the Giant's Causeway has been listed by UNESCO as a World Heritage Site, and with good reason. The area has been attracting tourists for many centuries and scientists, geologists and writers for 300 years or more.

As a Geographer and local to the area, I never tire of photographing and visiting this scenic part of the Irish coast.

To join me on a photography workshop of the Antrim Coast and the Giant's Causeway click here.