1. TauTona gold mine in South Africa  which is about 3.6 kilometers deep.
2. The mantle is 3,000 km of rock
3. If I was to dig to the mantle with my friends we would see volcanos, magma, and lava flowing out. While in the mantle it would be entirly red and things melting like if you were to put lava on plastic. The outer core would be like a hot yellow jellow that would jiggle and would lead into the inner core which is like a round ball of cheese and as bright as the sun which would be solid and hard. Basically nothing can get through it. When we found out we couldn't brake through we tried to escape and about 2 of my friends burned to death because they unzipped their heat suit.