Beneath the ruins of Reactor 4 at Chornobyl, there is a hidden but very dangerous nuclear mass called the Elephant's Foot. The mass is made of Corium, a mixture of molten lava, including uranium, zirconium, and concrete, created by the 1986 disaster. The radiation levels were so high that a five-minute exposure would have been fatal.
Now that much of the radiation has decayed, it is an impenetrable relic from the nuclear age. The density of such a mass (which previously required an AK-47 to chip off), together with the danger of inhaling radioactive dust, makes moving the mass nearly impossible using the available technology. The mass is now contained within a billion-dollar steel dome and serves as a terrifying, silent reminder that it will be there for the next 300 years. Despite its stability, the structure is slowly cracking, prompting researchers to monitor the site for potential radioactive dust dispersal risks.
