In the wake of World War II, Russia raced against the US to compete for atomic capabilities and ended up creating the most polluted place on Earth.
Radioactive waste from a nuclear plant was dumped into Lake Karachay for 40 years. Over 50 years later, the extensive damage that this caused was exposed, and the world discovered that the lake was more radioactive than Chernobyl.
This means that exposure to it could kill a human within an hour. It also means that, should it leak again, it could have disastrous effects on a global scale.
So, how did this happen, and what does it mean for the rest of the world? Click on to find out.