IFL Science reports that Karachay is "the most radioactive lake on Earth". Additionally, its waters are so highly irradiated that spending just an hour sunbathing on its shores could prove fatal.

Volcanic activity heats the groundwater to release an explosion of rock and steam. 8. Lake Karachay Lake Karachay is in Russia. It is a polluted, deep blue, deadly and toxic lake. It was used as a ...