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
Cave of the Crystals of the crystals. As the cave's accessibility is dependent on the mine's water pumps, when mineral exploitation is ended in the area it was likely pumping would stop and water level allowed to rise again. In February 2017, Penelope Boston reported to the BBC that mining operations had ceased and that the caves have re-flooded. Cave of the Crystals Cave of the Crystals or Giant Crystal Cave () is a cave connected to the Naica Mine at a depth of , in Naica, Chihuahua, Mexico. The main chamber contains giant selenite crystals (gypsum, CaSO·2 HO), some of the largest natural