It's the deepest man-made hole on Earth, made in a project between May ... In 1994, drilling officially ceased, and Russia awaited scientific advancements to continue drilling.

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 point, on Earth, measuring ...

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 ...

With a depth of around 2,199 metres, a cave in Georgia is so deep that nearly seven Eiffel Towers could fit inside.