Journey to the Centre of the Earth is the classic 1864 science fiction novel by Jules Verne.

It features German professor Von Hardwigg who is convinced that there are volcanic tubes going toward the center of the planet.

Hardwigg and his nephew travel with a guide named Hans through various epochs of geological time as they descend further into the earth, encountering strange monsters, beasts, and insects--all of which get older as they go deeper.

As Hollywood is wont to do, they made a movie out of Journey to the Center of the Earth, which is pretty lousy.

The book is way better than the movie. So get down (lol) with professor Hardwigg as he explores the interior of the Earth.