Wednesday, Aug 19, 2020, 2:27 pm

By:Tony Williams

#9 Radon Health Mine - Montana, US

Lead ore and silver mining was done in the Radon Mine in 1924, before it was abandoned. However, in 1949, when radioactivity was found to have cured a woman of her ailments when she entered the cave, it soon became a radon therapy mine. People actually sleep there, and come out feeling better.