Researchers say this sinkhole in the South China Sea is the deepest in the world. | CNN

The Kola Superdeep Borehole: The Deepest Point Ever Reached by Humans The Kola Superdeep Borehole remains one of humanity’s most ambitious scientific drilling projects. Launched in 1970 by Soviet scientists on the Kola Peninsula in northwestern Russia, the borehole eventually reached a depth of 12.2 kilometers (7.6 miles), making it the deepest artificial point ever created in Earth’s crust. The objective was not to search for oil or minerals, but to advance scientific understanding of the conti