Journey to the Center of the Earth by Jules Verne
I've read three of Verne's books now, the three biggies, Around the World in 80 Days, Twenty Thousand Leagues Under the Sea, and I just finished Journey to the Center of the Earth. As far as I can tell, here's what they all have in common, aside from the "journey" plot. Each has a lot of really boring parts interspersed with some thrilling, brief adventures. And I'm not sure the exciting parts outweigh the mind-numbing bits.
A geologist finds a hidden scrap of paper, deciphers what it says with the help of his nephew, and decides to follow what it says and make the journey to the center of the earth. They don't actually get there by the way. The geologist takes his nephew with him and they find a guide in Iceland.
What they do discover is a vast subterranean cavern. This underground world is lit by electrically charged gas at the ceiling and is filled with a very deep subterranean...