The Nautilus was built by Captain Nemo and his crew on the island of Vulcania after they escaped an unidentified prison camp. It sailed throughout the world's oceans, attacking various ships. As a result of its attacks, many believed it to be a sea monster. One expedition to try and find it resulted in the arrival of Pierre Aronnax, Ned Land, and Conseil, all three were captured and experienced many strange adventures, the most notable being an encounter with a Giant Squid. The Nautilus is also extremely advanced for its time, running off of nuclear power (as opposed to electricity in the original novel by Jules Verne).
The Nautilus appears on the show. Henry Mills and Violet finds a second version of the Fairytale book where there is an illustration representing Captain Nemo and the Nautilus. It was etablished that these stories exist in the Land of Untold Stories.
The Nautilus appears in the episode "Dark Waters", where Captain Hook was kidnapped and taken aboard by Captain Nemo in the past. The Nautilus is used by them to find a treasure, the key to the 'Mysterious Island', the Land of Untold Stories. It appears later in the episode in Storybrooke where Hook and Henry are kidnapped and taken aboard.
From 1955 to 1966 at Disneyland, the 20,000 Leagues Under the Sea exhibit In Tomorrowland featured many of the sets and props of the Nautilus for guests to view in person. Decades later for Disneyland Paris, the walkthrough was recreated complete with a submerged Nautilus facade, forming a mini-Jules Verne area with Discoveryland's From the Earth to the Moon inspired Space Mountain.
20,000 Leagues Under the Sea (ride)
At the Magic Kingdom's Fantasyland, an updated version of Disneyland's Submarine Voyage would take on more of the influence of the film with copies of the Nautilus serving as vehicles and an encounter with the giant squid. After the attraction closed in 1994 and the vehicles were gradually removed, the hull of one Nautilus was cut apart and taken temporarily to Disney's Hollywood Studios for the Backlot Tour's preshow, before being removed and brought out for pin events. Two other Nautilus were sent to Castaway Cay to be submerged in the snorkeling lagoon, though the ocean has already taken it's toll on the vehicles. The rest were buried in an onsite landfill after being stripped of various parts for collectors.
In Disneyland Park (Paris) The submarine is located in a lagoon near Space Mountain: Mission 2. Guests enter what looks like a lighthouse, and proceed into the attraction through an underwater corridor. Six rooms are visited inside the Nautilus.
An area in Tokyo DisneySea inspired by Vulcania, the Nautilus appears in the lagoon, though it is not the facade for a walkthrough like in Disneyland Paris.
The Nautilus appears under the name Notilus in the first area of Tomorrow City, where Mickey Mouse must raise it from the depths of a pool of thinner in a hidden cavern of ancient ruins. Mickey then rides the Notilus to the surface at the Tomorrow City Lagoon, by the Great Big Tomorrow exhibit.