Located in Northern Russia, the Kola Superdeep Borehole is the world’s deepest man-made hole to earth’s ground. It measures 40,226 feet or over 7.6 miles below the earth’s surface.
Considered to be the pride of Russian geology, the hole was created by the USSR and was the result of a scientific drilling project to drill as deep as possible to investigate the continental crust. The drilling began on May 24, 1970 on the Kola Peninsula, using an “Uralmash-4E” and later an “Uralmash-15000″ drilling rig. After 24 years the drilling was stopped because it was getting too hot inside it.
The site is currently controlled by the State Scientific Enterprise on Superdeep Drilling and Complex Investigations in the Earth’s Interior (GNPP Nedra) as the Deep Geolaboratory. As of 2003, the deepest active bore is SG-5, at 8,578 metres (28,143 ft) deep and 214 mm (8+7⁄16 in) in diameter.
In late 2005, the project was closed down due to lack of funding and all the equipment for drilling and research was scrapped. The site has been abandoned since 2008.