kola borehole
© Rakot13/CC BY-SA 3.0The Kola Superdeep Borehole can still be visited today and is hidden underneath this rusty lid
EARTH'S deepest artificial hole stretches 40,000 feet below the surface - but it's only covered by a rusty metal lid.

Russia's Kola Superdeep Borehole was created by the Soviets in the name of science so they could learn more about what's really under our feet and dig to depths unknown.

The project to drill into the Earth's surface began near Murmansk in the 1970s, when Soviet scientists wanted to learn more about the Earth's crust.

Over two decades, they managed dig more than 7.5 miles down into the Earth.

However, in 1992 they had to stop drilling because the temperature was around 180 degrees Celsius, which was far hotter than the scientists predicted it would be.

Experts still need to figure out a way to overcome this temperature issue if they want to keep drilling and not destroy all of their equipment in the process.

All this drilling wasn't for nothing though as some scientific discoveries were made.

The researchers found out that there is water at 12 kilometres into Earth's crust, despite this previously being thought to be impossible.

They also found 24 new types of long dead single celled organisms and gained access to rocks that were 2.7billion years old.
kola borehole
© WikicommonsThe hole is located at a derelict site, which was once a Soviet research facility
The Kola Superdeep Borehole is 23 centimetres in diameter and its metal lid is welded on so it is unlikely that anyone would ever fall down it.

Locals in the area say that the hole is so deep you can hear the screams of people being tortured in hell, hence its nickname being 'the well to hell'.

If you fell down the hole, it would take around 3.5 to 4 minutes to reach the bottom.

Lots of countries wanted to be the first to drill into the Earth's mantle during the Cold War and today Japan is attempting to set this record.

kola bore hole
© Getty - ContributorThis is the equipment that created the record breaking hole
kola borehole
© Getty - ContributorThe Soviets started drilling as a scientific experiment in the 1970s

What is the Kola Borehole deeper than?

Basically everything but here are some impressively large things that it beats in size...
  • The Kola Borehole is 40,230 feet deep making it the deepest man made point on Earth
  • That makes it much longer than the UK's highest mountain, Ben Nevis, which stands at 4,409 feet
  • The shard is only 1020 feet tall to its tip
  • The Burj Khalifa is the tallest building in the world and is 2,717 feet high
  • The Kola Borehole is also further down that the wreck of the Titanic, which is 12,500 feet down in the ocean
  • However, the Z-44 Chayvo well is now the longest man made hole in the world but the Kola Superdeep Borehole is technically still deeper due to postioning
kola borehole