The Inco Superstack in Sudbury, Ontario, with a height of , is the tallest chimney in Canada and the Western hemisphere, and the second tallest freestanding chimney in the world after the GRES-2 Power Station in Kazakhstan. It is also the second tallest freestanding structure of any type in Canada, behind the CN Tower but ahead of First Canadian Place. It is the 40th tallest freestanding structure in the world. The Superstack is located on top of the largest nickel smelting operation in the world at Vale's Copper Cliff processing facility in the city of Greater Sudbury.