The Giant's Causeway (known as Clochán an Aifir or Clochán na bhFomhórach in Irish 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 metres (39 ft) high, and the solidified lava in the cliffs is 28 metres thick in places.