But things changed in the 20th century, when machines allowed us to dig deep into the Earth. But how deep have we reached, really? In this gallery, we bring you the deepest holes on Earth—both ...

Scientists have dug the deepest hole ever in rock from Earth's mantle, drilling more than 4,160 feet in the North Atlantic ocean. The team of researchers used an ocean drilling vessel to dig into ...

It's currently the deepest man-made hole on Earth, reaching a dizzying 40,230 feet below ground. The Kola Superdeep Borehole is locked away beneath a rusty lidCredit: Rakot13/CC BY-SA 3.0 This ...

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 ...