Monster Island is located in the sea of Japan at longitude 136, latitude 40 degrees north, Monster Island is perhaps the most famous dwelling place for monsters in the world. The small and ruthless Mole Man used the Island as his base of operations.
It got its name from the strange monsters
that inhabit this would be paradise. The island has caverns that run down into the Earth’s core, these caverns connected the island to the Continents of the planet. The caverns also provide refuge for the subterranean monsters.
The Mole Man established himself in Subterranea, which would become his underground empire. He learned to master the strange creatures.
Monster Island was thought to be destroyed by the Mole man in his attempt to destroy the surface world, by using an under ground atomic explosion. The Island appeared showing no signs of harm. Much later the golden protector of the Infinity Gems, Adam Warlock and the Infinity Watch later used the Island as their base of operations.
Although the Mole Man claimed the island for his underground empire, the United Nations
never recognized it as a nation of its own. They have made several attempts to invade the island.