German Continental Deep Drilling Programme
The German Continental Deep Drilling Programme (German: Kontinentales Tiefbohrprogramm der Bundesrepublik Deutschland, lit. 'Continental deep-drilling program of the Federal Republic of Germany'), abbreviated as the KTB borehole, was a scientific drilling project carried out from 1987 to 1995 near Windischeschenbach, Bavaria. The main super-deep borehole reached a depth of 9,101 m (29,859 feet) in the Earth's continental crust.
Source: Wikipedia — German Continental Deep Drilling Programme (CC BY-SA 4.0)