Berkeley Pit – the most dangerous and toxic lake (7 pics)
In fact, it's not a natural lake, it’s a former open pit copper mine. It is situated in Butte, Montana, USA, and it is filled with 30 billion gallons of deadly toxic water (mix of heavy metals and poisonous chemicals). When this enormous mine was closed in 1982, groundwater began to leak into the basin – disastrously passing through the metal deposits in the soil. The water here was responsible for killing 342 snowgeese who landed there and died in 1995.