A Monster Island-like locale would show up again in two Heisei films, Godzilla vs. King Ghidorah (Lagos Island), and Godzilla vs. SpaceGodzilla (Birth Island) though the convention has not reappeared in a film since then.
- Main article: Solgell Island.
Monster Island first appeared in the 1967 Toho film Son of Godzilla as Solgell Island. The island had became very warm after an experiment with weather control systems had gone wrong, resulting in the appearances of Kamacuras, Kumonga and Minilla, who hatched prematurely from his egg after the Kamacuras attacked it. Minilla's cries of distress attracted Godzilla to the island. After Godzilla had rescued and bonded with his new adopted son, and worked together with him to repel Kumonga, a second weather experiment was successful, and heavy snowfall forced Godzilla and Minilla to go to sleep. Over time, the ice and snow thawed out, and the humans built a research station on the island. Finally, the island was renamed to Monster Island.
In this film, a variant of Monster Island appears within the imagination of the main protagonist, Ichiro Miki. Many more monsters live on Monster Island, including Mothra, Manda, Gorosaurus and Baragon, as well as two new monsters that have origins in Ichiro's real-life experiences, Gabara and the Maneaters. In his dreams, Ichiro journeys alongside Minilla as they both learn to fend off Gabara, with Godzilla coming along to help.
Monster Island appears once again in this film, and serves as a home for Godzilla, Anguirus and several other monsters. Godzilla and Anguirus break out of the Island's containment systems after they learn of Gigan and King Ghidorah's arrival on Earth.
After defeating the alien monsters in the previous film, Godzilla and Anguirus journey home to Monster Island. Anguirus and Rodan are resting when suddenly, a nuclear test nearby shakes the island! The ground begin to open up, and Rodan tries to escape, but Anguirus falls on him, plunging both of them into an underground fissure. Whilst Rodan's whereabouts were unknown, Anguirus would reappear the following year, having survived the fall and a subsequent journey under the Japanese countryside. The destruction of the island promptly forced the Seatopians to attack Japan, as the resulting earthquake caused by the sinking island severely damaged the capital of Seatopia.
During the Monster Wars trilogy the Isle Diablo island chain (or Site Omega, as the aliens called it) was taken over by the Tachyons in their plot to take over the world. They used the island as a staging point to gather earth's monsters and send them after 6 of the worlds most powerful nations on the planet in a bid to weaken earth's defenses and colonize earth. They were ultimately defeated and most of the Monsters killed in the process.
Three Survivors Crustaceous Rex, the Giant Bat, and King Cobra were rounded up and imprisoned on the island. The island utilized massive force fields to keep King Cobra and Crustaceous Rex from fighting the Giant Bat was allowed to roam freely but prevented from using its sonic shrieks by a special collar and kept from leaving the island by lasers.
Later the terrorist organization S.C.A.L.E. was able to find and sneak into the facility by smuggling a tracking device onto the H.E.A.T. Seeker when it went to the island to study a new captive known as Skeetera a giant mutant mosquito. They quickly took over the island, took both H.E.A.T. and the military personnel captive and set the Monsters Free.
Zilla Junior also broke into the Island to protect his adoptive father Nick Tatopoulos and pacified the monsters which gave a needed opening to regain control over the island. In other episodes, numerous other monsters were also captured by the military: Giant Mutant Hummingbirds, The Shrewster, numerous monsters from the Mutant Mania circus, and numerous monsters from the Spiel Coliseum.
In an alternate timeline where engineered monsters known as D.R.A.G.M.A.s have ravaged the planet, an elderly Anthony Hicks mentioned releasing every monster on Monster Island in a desperate attempt to stop the creatures, but even they fell.
Monsters On Monster Island
In Stock Footage
These monsters lived in Monster Island but only in Ichiro Miki's dream, meaning they never truly existed on the island.
These monsters were imprisoned on the island in Godzilla: The Series.
The Giant Mutant Hummingbirds were said to be brought to Monster Island, but were never seen there.
These monsters were possibly imprisoned too on the island later but it was never confirmed.
- Mutant Rat (the biggest one with the dark skin)
In Video Games
Monster Island has appeared in Atari's Godzilla games. In Godzilla: Save the Earth, it is a playable arena that has a sub-arena, Monster Island Bay. The island has a mud pit, a waterfall, and even a volcanic section. Some of the challenges like Vorillium Basketball and Monster Bowling appear to take place on Monster Island, but its never actually said whether they do or not.
In Godzilla: Unleashed, the island is the first location to be bombarded with the crystals. The resulting chaos lets the Earth Defenders successfully deactivate the forcefield barriers and escape. In Godzilla Unleashed: Double Smash, the monsters are released as in Unleashed, but end up returning there for the final battle against Destoroyah and SpaceGodzilla.
Monster Island has, so far, appeared in three comics by IDW Publishing. In Godzilla: Gangsters and Goliaths, it is an island that seems to be a mixture of Monster Island and Infant Island with the presence of Mothra and the Elias. Monster Island also appears in Godzilla: Ongoing as a containment island much like the original where the monsters defeated by Boxer and his Monster Wrecking Crew are rounded up to be used as weapons. Eventually, the monsters are set free from the island by Kiryu in order to help fight off the space monsters invading Earth. In Godzilla: Rulers of Earth, an entire chain of islands dubbed the "Monster Islands" is set aside to contain captured monsters. The monsters on these islands are transported there by CKR mechas Kiryu, Jet Jaguar, and M.O.G.U.E.R.A. and are observed by a team of scientists.
- During the late 60's and early 70's, Monster Island was frequently used as a way to get Godzilla and any other monsters involved, into the movie without a lot of back story, especially in Godzilla vs. Gigan and Godzilla vs. Megalon. However, by the time that Terror of MechaGodzilla rolled around, Godzilla simply appeared on cue. It was also a way for the producers to fill up time by including stock footage of the other monsters.
- In Godzilla: Awakening, the prequel comic to the 2014 film, Godzilla battles Shinomura on an island called "Moansta Island," a clear reference to Monster Island.