The World Heritage site of the Giant’s Causeway lies within the Causeway Coast, an Area of Outstanding Natural Beauty which covers 18 miles of dramatic cliffs, headlands and a series of bays.
The spectacular coastal scenery of the Giant’s Causeway is formed by surface outcrops which are entirely in the Tertiary Basalts. The cliff-like edge of the plateau, the varied structure and colour of the basalts and inter-basaltic beds and the subsequent differential erosion of the different rock and soil types have resulted in a unique arrangement of features which are of outstanding scenic quality and geological interest.
The headland consists of lavas which have resisted the persistent erosion of the sea with the northern most promontory, Benbane Head, formed by the local occurrence of two unusually massive and resistant lavas. The cliffs have an average height of some 100 metres and along most of the coastline have a stepped appearance with a succession of five or six lava flows clearly visible in some locations. While the low promontory of the Giant’s Causeway displays in great detail the columnar basalt structures for which the site is famous, the Causeway Coast to the east clearly illustrates the geological succession of the Tertiary period in cross-sections of outstanding clarity.