The Giant's Causeway, Bushmills, Northern Ireland, UK (© Chiara Salvadori/Getty Images)

The Giant's Causeway, Bushmills, Northern Ireland, UK (© Chiara Salvadori/Getty Images)

In the footsteps of giants.

Let's follow in the footsteps of giants, this is one of the most popular tourist attractions in Northern Ireland. The Giant's Causeway is an area of about 40,000 interlocking basalt columns, the result of an ancient volcanic fissure eruption. It was declared a World Heritage Site by UNESCO in 1986 and a national nature reserve in 1987 by the Department of the Environment for Northern Ireland. The tops of the columns form stepping stones that lead from the cliff foot and disappear under the sea. Most of the columns are hexagonal, although there are also some with four, five, seven, or eight sides. The tallest are about 12 meters (39 ft) high, and the solidified lava in the cliffs is 28 meters (92 ft) thick in places.