Deep in the Arctic Circle, in Russia, lies the deepest hole ever dug which was once called 'the entrance to hell'. The Kola Superdeep Borehole is the deepest manmade hole, and deepest artificial ...

America might have landed on the moon, but Russia drilled the deepest man-made hole on Earth. Since the early 1960s, scientists have attempted to drill down to the Earth's mantle. It took 20 years ...

Russia’s Kola Superdeep Borehole SG-3 with a vertical depth of 12,262 metres completed in 1989 was regarded as the world’s deepest human-made hole on Earth.