The depths of Earth have puzzled the scientific community for millennia. For many years, we only had access to natural holes, even though many haven't been explored until fairly recently.

Reaching the geothermal energy far beneath our feet will require digging further into the Earth's crust than ever before.

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 ...

If we were to journey to the center of the Earth ... Here's how deep humans have dug underground. The typical grave is 6 feet down. Most Olympic swimming pools are 10 feet deep.

The deepest hole ever dug by humans dates back to the Cold War, however, when there was a race between the superpowers to drill as far into the Earth's crust ... 6,000C (10,832F) – is another ...