Las Médulas, El Bierzo, León, Spain - stock photo

Located in El Bierzo next to the Sil River Valley, Las Médulas are an impressive Spanish landscape environment formed as a result of Roman gold mining. Considered the largest open pit gold mine in the entire Roman Empire, the engineering work that went into extracting the gold significantly altered the environment in the area, resulting in an unusual red sand landscape covered in chestnut and oak trees. This environment was declared "Asset of Cultural Interest" in 1996 due to its archaeological interest. In 1997 Unesco declared it a World Heritage Site, in 2002 it was awarded the title of "Natural Monument" and in 2010 "Cultural Space".