the farthest distance below Earth's surface that a human has traveled is about 7.6 miles (12.3 kilometers). This record was set by the three crew members of the Soviet Union's Kola Superdeep Borehole, which reached a depth of 7.6 miles in 1989. The Kola Superdeep Borehole was a scientific drilling project aimed at studying the Earth's crust and collecting geological samples.
It's important to note that this depth represents the deepest point humans have directly reached on Earth. There are naturally occurring deep cavities and underground systems, such as caves and mines, that can extend deeper than the Kola Superdeep Borehole. However, these locations are generally explored with specialized equipment and not by humans directly descending to those depths.