1. The Kola Superdeep Borehole
Depth: 7.5 miles (12,261m)
The deepest hole in the world is the Kola Superdeep borhole, in Murmansk Russia. The drilling started in 1970, and it was finished in 1994, they had to stop the drilling because the temperatures were too high at the depth that they reached. Fossils of 24 ancient species were excavated, during the project. The hole was sealed with a metal cap in 2005, and the project was finished. We hope our list of 10 biggest deepest holes in the world, satisfied your curiosity.
