20,000 Leagues Under the Sea, by Jules Verne Sea monsters and the first steampunk submarine: it doesn’t get more adventurous than that. Verne’s classic work of adventure and sci-fi isn’t exactly scientifically rigorous—at one point Captain Nemo exits his submarine and strolls about on the floor of the ocean without difficulty—but its spirit of discovery, as Nemo and companions travel to various incredible places (including the lost city of Atlantis), is unparalleled.