Mysterious Island is named after a Jules Verne novel and it is the setting for a central port of call in Tokyo DisneySea, around Mount Prometheus, the park icon.  Transit Steamers pass by the island on the way to Mediterranean Harbor but do not stop as they go by the Nautilus.  Captain Nemo’s presence, like  in the novel the port is inspired by, is felt through the volcano’s caldera and in one of the attraction, 20 000 Leagues Under The Sea.   This dry dark ride uses suspended ride vehicles with water-filled windows to give the illusion that we are deep under the ocean.  This avoids all the maintenance challenges and costs that the attraction of the same name suffered from in Florida when it ran at Magic Kingdom as actual submerged submarines. 

The other attraction is the park’s headliner and signature ride.  Journey to the Center of the Earth was initially though to be a freefall attraction, placed inside a volcano structure when Disneyland Paris was planning Discovery Mountain as a massive indoor area.  When Discovery Mountain plans were revised to be more practical and to reflect the Paris resort’s financial challenges, the freefall attraction was not kept.  When it came time for Tokyo DisneySea, Journey to the Center of the Earth idea of venturing into the earth core transformed into a massive ground breaking dark ride, placed inside the most unusual show building, Mt. Prometheus itself.

Disney went to the Slot Car system they had developed for Test Track at Epcot for the ride system.  After learning from all the challenges plaguing Test Track during development, Journey to the Center of the Earth ride vehicles were redesigned to solve those.  For example, Test Track small wide tires lead to performance issues and have wear and tear problems.  The tire size was mandated for Test Track due to the vehicle’s shape and theme. At the same time, for Journey, they could start with a clean slate and adapt the cars to whatever would be best from an engineering and reliability point of view.  Another operational challenge for Test Track is the three across seats.  The presence of a single rider’s line help, but knowing that most guests travel either as couples or as families makes it challenging for the cast members to keep the seats filled.

WDI went with a massive iron steam-powered mine car to address those concerns.  Guests sit two across in three rows, restrained with a lap bar, perfect for the groupers (cast members who assigned seating to guests.)  The car’s much bigger footprint and taller seats allowed WDI to forgo the small tires for massive truck-sized tires that can take the loads better.  This was critical due to the final ride element exposing the mine cars to high stress.

Guests will not find an outdoor marquee for the attraction.  Instead, as guests explore the caves at the bottom of Mount Prometheus, they come across steampunk-esque machines that deliver fast passes and an impressive lava formation.  This is the ride entrance; as guests enter the massive cave that houses the queue, they pass by steam coming out from the ground and various laboratories where Nemo’s team researches the incredible things found deep within the earth’s core.

Guests eventually arrive at the Terravators.  Those four steam-powered elevators take guests deep underground to the base where mine exploration vehicles go out to explore a safe path.  The Terravator goes down a half mile in a loud fashion and exposes us to heat and various lights before safely delivering us to the mine car departure area. 

Large steam-powered bellows provide fresh air from the surface as ride vehicles regularly depart into the caves.  As we go down in the queue, we pass by a communication station where someone in Japanese calls out that there are earthquakes in the safe path and it is not safe to proceed.  Alas, the communication officer is away for tea, so the warning goes unheeded.  Three ride cars are loaded at once in a dedicated loading area. 

Mine cars venture out in the first cave, the Crystal cavern, as hauntingly beautiful music starts playing.   Passing on a suspension bridge near a waterfall, the car goes down as giant earthworms borrow rapidly around us.  The mushroom forest follows as we see beautiful creatures in a glowing mushroom-filled area bounce around, very friendly toward us.

Exiting the forest, we see that the earthquakes mentioned in the queue have blocked the way ahead.  As a crew member frantically calls us, the cars turn to the left instead, venturing into an uncharted area.  Things heat up literally as the corridor is filled with steam as we see odd giant eggs, and the rock walls glow from the ambient heat.  We then arrive at a massive indoor sea on our right.  The music turns ominous as lightning strikes near us, using a tesla coil soon after.

We arrive in an area filled with lava, and as the car barely climbs up a steep hill, we see a massive fireball on the left in an alcove!  It’s a brilliant distraction as on our right, standing in a lava pool, we have the source of all those eggs we saw earlier.  The giant Lava Monster is not happy to see us and threatens us as it tries to lunge at us.  We are saved by a sudden buildup of steam that quickly accelerates our mine car out of danger.  

In a cloud of steam, the car does a rising 360° spiral that straightens out at the top.  Still rising, the car goes outside, dropping down a perfect parabolic hill that allows riders to experience a brief moment of weightlessness.   Standing over 50 feet tall, this fantastic drop allows the car to reach 45 mph.  Before entering a cave in the middle of a banked curve, it starts decelerating until it reaches a slow speed before returning to unload.

Guests exit the cars, then proceed down a compact staircase nearly three stories to return to the caves. 

The ride secrets:

The combination of all the tricks and special effects used here is incredible.  The borrowing worms are created by placing vacuum tubes on the walls.  Air is injected, causing the worms to move rapidly and in a seemingly random fashion, thanks to the precise way they are lit and placed in general darkness.  U/V reflective paint is used in the Mushroom Forest and on the creatures, giving a fantastic look that was later used on Nav’I River Journey at Disney’s Animal Kingdom. 

The ride uses very warm and hot colors and lighting in the second half to differentiate itself from Indiana Jones Adventure at the park. The use of hot steam, smoke, and the perfect application of fire create chaos and a feeling of danger in the second half.  The fireball allows an amazing reveal of the lava monster.  Before, the Tesla Coil was loud and close enough that riders truly felt like lightning struck the rock.

The Terravators are actual elevators, programmed to feel like they are going down.  In reality, they go up 3 to 4 stories to deliver guests to the loading station.  Disabled guests use a small lift at load to go down to unload to board their ride vehicle.  Then, upon exiting, they return to the Terravators using the same small lift.  They ride a terravator in reverse so they can exit out the attraction through the VIP entrance.

The music is incredible, as this was the last ever score composed by legendary in-house Disney composer Buddy Baker.  Buddy Baker composed the famous Haunted Mansion and Pirates of the Caribbean music, and arranged the themes of Winnie the Pooh and other famous Disney movies and attractions.  Journey to the Center of the Earth was his final composition a year before he passed away in 2002.