Here's a breakdown:
* Crust: This is the solid, rocky outer layer of the Earth. It's relatively thin, ranging from about 3-5 miles (5-8 kilometers) thick under the oceans (oceanic crust) to about 25 miles (40 kilometers) thick under the continents (continental crust).
* Mantle: Beneath the crust lies the mantle, a thick layer of mostly solid rock that makes up about 84% of Earth's volume.
* Core: At the Earth's center is the core, which is divided into a liquid outer core and a solid inner core.
So, while you can't see it, the crust is definitely under the surface of the Earth!