Giant's Causeway rocks in Northern Ireland now suffer from tourists wedging coins into 40,000 basalt columns, turning this UNESCO site into a battered piggy bank. National Trust officials warn the rusting metal is damaging 60-million-year-old stone: “Corners have popped off.”

Officials say the Loom, a 10 ft high formation, is now stained reddish-brown by rusting coins. A specialist stonemason has removed about 10% so far, aiming to halt this quirky tourist habit. Tour guides urge: “Take a photo—leave the rocks alone.” The result: a patchwork of rusty hexagons.

In 2019, nearly 1 million visitors and thousands of coins left a visible coppery wash across the iconic black basalt.