The Kola Superdeep Borehole, although only 9 inches in diameter ... World's top 5 national parks to see the coolest wild animals Why delve so deep into the Earth's crust? According to Dr.

The Kola Superdeep Borehole, dug during the Cold War, remains the deepest hole ever made by humanity. In this video, we explore the science, history, and fascinating discoveries behind this ...

Here's how deep humans have dug underground ... Mponeng in South Africa is the world's deepest gold mine. The Kola Superdeep Borehole is only 9 inches wide. Russian scientists have been drilling ...