20 Out-Worldly Places On Earth That Look So Unrealistic, But They Aren't

Naica Mine, Mexico: Naica began operations in 1794 and was taken over by Grupo Peñoles in 1952. The underground mine is serviced by a number of shafts, declines, and spiral ramps. The mine is situated on a structural dome measuring about 12 km by 7 km. Country rock is a thickly bedded Cretaceous limestone.