The Earth’s mantle lies beneath the Earth’s crust, and to reach it, we would need to dig quite deep. On average, the mantle starts roughly 30 kilometers (about 18.6 miles) below the surface under the continents and around 5 to 10 kilometers (about 3 to 6 miles) below the ocean floors.
However, digging to this depth is a monumental challenge. The deepest humans have ever drilled is the Kola Superdeep Borehole in Russia, which reached about 12 kilometers (7.5 miles) deep. This project encountered extreme temperatures and pressures, making it increasingly difficult to drill deeper. Further challenges include the geological formations and the costs associated with such an extensive operation.
In conclusion, while the mantle is several kilometers below our feet, practically reaching it is a task that remains largely unachieved due to technological and physical limitations.