Twenty Thousand Leagues Under the Sea by Jules Verne

An early science fiction novel by Jules Verne, telling the adventures of Professor Aronnax, his servant Conseil, and harpooner Ned Land aboard the submarine Nautilus commanded by Captain Nemo. The trio set out to hunt a mysterious sea monster, only to discover the advanced submarine and become unwilling passengers on an extraordinary underwater journey. The story explores themes of exploration, technology, and humanity's quest for knowledge, and has inspired numerous film adaptations.