Slovenia: Idrija Mercury Mine

The Idrija Mercury Mine the oldest and second-largest mercury mine in the world, recognized as a UNESCO World Heritage site. Mercury was discovered in Idrija around 1490 by a villager who found liquid mercury metal in a stream. Mining began in 1500 and the mine operated for nearly 500 years until its closure in 1995 due to mercury price collapse and environmental issues. At its peak it produced 13% of the world’s mercury, yielding over 147 thousand tons of the liquid metal. The mine is unique for containing mercury in both its liquid pure form and as cinnabar (mercury sulfide) ore. You can see both forms on a tour of the mine that takes you deep underground down the Anthony’s shaft that was originally dug out in 1500. You also learn a bit the harsh working condition of the past in the mine – mercury poisoning was devastating as nobody was wearing any masks. The area around the mine and all the streams are still quite polluted.