Idrija is a lovely town situated in western Slovenia that comes highly recommended. But what’s more, it’s also the location of a UNESCO protected ancient mercury mine. Back in 1490, a tub maker soaking his tub in a creek discovered droplets of strange shiny material, which turned out to be mercury. Idrija soon became the oldest Slovenian mining town, which used to supply Europe with this valuable liquid metal. Today, this hidden gem is a museum where visitors can descend into the subterranean world along the trail of Idrija’s miners and marvel at the town’s precious mining tradition. Legend has it, a mine elf called Perkmandlc (if you can pronounce it) still resides deep in the underground. Idrija’s mercury mine museum is exceptionally educational and fun and should definitely be visited when in the area. Besides the mercury heritage, Idrija is famous for its exceptional lace making, which has also been listed under UNESCO’s protection.It’s also a superb basecamp for exploring the wider area.