Giant's Causeway with higher saline content than that found at the causeway. Although the basaltic columns of the Giant's Causeway are impressive, they are not unique. Basalt columns are a common volcanic feature, and they occur on many scales (because faster cooling produces smaller columns). The Belfast-Derry railway line run by Northern Ireland Railways connects to Coleraine and along the Coleraine-Portrush branch line to Portrush. Local Ulsterbus provide connections to the railway stations. There is a scenic walk of 7 miles from Portrush alongside Dunluce Castle and the Giant's Causeway and Bushmills Railway. Giant's Causeway The Giant's Causeway is an area of
Rushmore Cave into a rock known as limestone. The cave has a cornucopia of rooms including the Entrance Room, Post Office, Image Room, Big Room, Fairyland, Rope Room, Geode Room, The Rouge Room (Party Room), Arrowhead Room, and the Floral Room. The cave also includes boxwork and many dripstone formations including stalactites, stalagmites, columns, helictites and flowstone. Rushmore Cave Rushmore Cave is the closest show cave to Mount Rushmore National Memorial in the United States. It contains a wide variety of natural formations. It is the ninth longest cave in South Dakota. It measures a distance of . It was discovered in