Stone-Ideas.com 
At the Giant’s Causeway, the world-famous natural monument on the Northern Ireland coast, about 100 km from Belfast, tourists are causing serious damage: Many people press coins into the cracks in the basalt rock. Dr. Cliff Henry of the National Trust politely asked visitors in a press release to stop this bad habit: “We know some visitors may want to leave a token of their visit, but we are urging them to stop the practice so this natural wonder remains special for future generations.”
The rust and oxidation causes the coin metal to swell, which cracks the stone, according to a report by the British Geological Survey. Furthermore, the rusty water that runs off leaves unsightly marks on the surfaces of the stones. These are mostly iron, nickel, and copper, and the coins primarily originate from the United Kingdom, but also from the Eurozone and even the Far East or the USA.
The National Trust has now commissioned the problem to be examined at ten test sites. They say the coins could be removed, but the cost would be more than £30,000. Moreover, the measure doesn’t make much sense as long as this bad practice doesn’t end.
The Causeway, with its approximately 40,000 geometric basalt columns, is a Unesco World Heritage Site. According to legend, it was created by the Irish giant Finn McCool, who crossed the sea on the causeway to fight his Scottish rival, Benandonner. However, he was tricked by the Scotsman’s wife, who disguised her husband as a baby. The Irishman then believed that there must be a race of supergiants in Scotland and fled.
According to another legend, Finn wanted to use the causeway to reach a Scottish maid with whom he was in love. Further details are unknown.
The geological explanation is more sober, but no less fascinating, and refers to the hot volcanic mass that rose with the formation of the Atlantic Ocean 60 million years ago and solidified through slow cooling in the water. The cause of the regularly shaped, vertical columns is tension cracks in the stone. The phenomenon is also known elsewhere, albeit not on such impressive scale.
Photos: National Trust
