The Kola Superdeep Borehole is the deepest hole in the world. How deep is it?

The Kola Superdeep Borehole is the result of a scientific drilling project of the former Soviet Union (now Russia) in the Pechengsky District, on the Kola Peninsula. The project attempted to drill as deep as possible into the Earth's crust. Drilling began on 24 May, 1970 using the Uralmash-4E, and later the Uralmash-15000 series drilling rig. A number of boreholes were drilled by branching from a central hole. The deepest, SG-3, reached 40,230 ft in 1989. In terms of true depth, it is the deepest hole and artificial point on earth.