Minerals is what South Ural is rich in. In the 1930s they made a lot of open pits in the Chelyabinsk region of Russia. The most famous of them is the Korkinsky one. But others deserve some attention too. For example, the Krasnogorsk mine is quite impressive. There is an artificial pond in its bottom which looks like a small mountain lake.
That dump pit is 80 meters (260 ft) high.
The mine is not functioning anymore but it still attracts visitors with its beauty. The mine is 150m (500 ft) deep.