Standing by this Russian lake for an hour could be lethal

Lake Karachay in the Ural Mountains became a dumping ground for Soviet nuclear waste starting in 1951. A 1993 study put its accumulated radioactivity at around 120 million curies, and roughly an hour on its shore could deliver a fatal dose. It was finally sealed under concrete and rock by 2015.

— Wikipedia contributors, Pollution of Lake Karachay — geographic reference entry