Northern Ireland
The Giants Causeway - The result of an ancient volcanic fissure eruption, is located in County Antrim on the north coast of Northern Ireland, about three miles (5 km) northeast of the town of Bushmills.
It was declared a World Heritage Site by UNESCO in 1986 and a national nature reserve by the Department of the Environment for Northern Ireland in 1987. In a 2005 poll of Radio Times readers, the Giant's Causeway was named the fourth-greatest natural wonder in the United Kingdom.
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 some have four, five, seven or eight sides.The tallest are about 12 metres high, and the solidified lava in the cliffs is 28 metres thick in places.
Much of the Giant's Causeway and Causeway Coast World Heritage Site is owned and managed by the National Trust.