Question: have we drilled into the mantle?
Answer: This is the Kola Superdeep Borehole, the deepest manmade hole on Earth and deepest artificial point on Earth. ... The Soviets' superdeep borehole isn't alone. During the Cold War, there was a race by the superpowers to drill as deep as possible into the Earth's crust – and even to reach the mantle of the planet itself.