World’s DEEPEST underground STRUCTURES, represented on a real scale, mines, caves, cities, tunnels, installations, etc.
Depth is measured from the lowest point to the surface, not to sea level.
World's Deepest Underground Structures
World’s DEEPEST underground STRUCTURES, represented on a real scale, mines, caves, cities, tunnels, installations, etc.
Depth is measured from the lowest point to the surface, not to sea level.