What is the deepest whole ever dug by mankind?
the deepest hole ever dug by mankind was one in Murmansk, Russia in an effort to penetrate the Earth’s Mantle for geologic study. At last count it had reached a depth of 40,000 feet (12,192 Meters) and had taken over 40 years to dig with modern technology. Unfortunately, it was unsuccessful at penetrating the Earth’s Mantle. http://www.seawana.com/conspiracy.