Overview

• Tourists have jammed various coins—including UK, euro, US and Asian currencies—into fissures of the basalt columns, which then rust and expand, exerting pressure on the adjacent rock.
• A British Geological Survey analysis cites “expansive delamination” of oxidizing coins as the cause of rapid erosion and unsightly streaking on the site.
• The National Trust, working with Causeway Coast and Glens Heritage Trust, has hired stone conservation experts to extract coins from ten test locations at a cost of more than £30,000.
• Chemical leaching from corroded coins has stained the columns with iron, nickel and copper oxides and caused flaking in notable formations such as The Loom.
• Managers are urging the 684,000 annual visitors to adopt leave-no-trace practices and refrain from leaving mementos to safeguard Northern Ireland’s first UNESCO World Heritage Site.