Professor Lidenbrock, Axel and Hans Bjelke find and enter the volcanic crater that marks the entrance to the centre of the Earth. Inside they face several difficulties and see a lot of strange things, including prehistoric life. They reach a vast underground cavern filled with a deep ocean, surrounded by a coastline.
The travelers build a raft and set sail on the ocean and reach a coastline. They enter a passage that they assume is the way ahead but discover that it is blocked by cave-in. They blast the rock but the explosion causes the sea to rush in. They are swept into a large vent filling with water and magma and are ejected onto the surface.
When they regain consciousness, they find out that they are on the island of Stromboli in Italy. The travelers return home to Germany. In Germany they are treated like heroes and Professor Lidenbrock's achievements are recognised. Axel marries Gretchen, and Hans eventually returns to Iceland.