This UNESCO cover from Spain depicts a miniature sheet issued in 2022 celebrating
Almadén and Idrija.
Heritage of Mercury. Almadén and Idrija is a joint UNESCO World Heritage Site in Almadén, Castile-La Mancha, 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. The sites bear testimony to the intercontinental trade in mercury which generated important exchanges between Europe and America over the centuries. The two sites represent the two largest mercury mines in the world and were operational until recent times. Mercury played an important role in extracting gold and silver from ores, dug in American mines. In addition, both sites illustrate the various industrial, territorial, urban and social elements of a specific sociotechnical system in the mining and metal production industries. At the heart of the Almadén site is a Mining Park, where the public can go underground. There are also buildings relating to the town's mining history, including Retamar Castle, the San Rafael Mining Hospital (now an archive), and eighteenth-century dwellings which form a hexagonal bullring.The site in Idrija notably features mercury stores and infrastructure, as well as miners’ living quarters, and a miners’ theatre.
