An oily tailings pond, seen from above, in the Athabasca tar sands region. Canada's tar sands are an oil reserve the size of England. Extracting the crude oil called bitumen from underneath unspoiled wilderness requires a massive industrialized effort with far-reaching impacts on the land, air, water, and climate. This photo was taken during the production of "Petropolis", a documentary film about the tar sands, directed by Peter Mettler and produced by Greenpeace Canada. For more information about this project, please go to: www.petropolis-film.com