Tags: World Heritage Site.
Heritage of Mercury. Almadén and Idrija is a joint UNESCO World Heritage site in Almadén Spain and Idrija Slovenia.The property encompasses two mercury mining sites. In Almadén mercury has been extracted since Antiquity while in Idrija it was first found in 1490 A.D. The Almadén site includes buildings relating to its mining history including Retamar Castle religious buildings and traditional dwellings.