The mining of mineral resources had drastic effects on nature in 20th-century Europe. Mines from earlier periods, such as the salt mine at Wieliczka in Poland featured in the photograph which has become a UNESCO World Heritage Site, appear almost idyllic by comparison.
Salt Mine at Wieliczka, photographer: Marek Czerwiński, colour photograph, 2007; image source: Wikimedia Commons, http://commons.wikimedia.org/wiki/File:Kopalnia_Soli_Wieliczka-Komora_Weimar.jpg. Creative Commons Attribution ShareAlike 3.0 Germany.