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 ...

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 ...

1959. By 1960, the bathyscaphe Trieste – piloted by Jacques Piccard and Don Walsh – reached the deepest known point on Earth’s surface: the Challenger Deep, located within the Mariana Trench ...

China live-streamed footage of its new manned submersible parked at the bottom of the Mariana Trench on Friday, part of a historic mission into the deepest ... in the Earth's crust that is deeper ...