The Ocean Between

Written by contributors to the Kingdom Hearts Wiki

"Legend has it that long ago, there was one single world that was constantly bathed in the warmth of the light of Kingdom Hearts.
"In the "age of fairy tales", the world was whole and full of light, which was believed to come from Kingdom Hearts, which was protected by its counterpart, the χ-blade. Over time, people came to desire the power of Kingdom Hearts, introducing darkness into the World.
"In order to take control of Kingdom Hearts, many people forged Keyblades in the image of the χ-blade, and they clashed together in a far-reaching conflict that embroiled the entire World. This event became known as the Keyblade War. In the end, darkness covered the World, the χ-blade was shattered into twenty pieces, seven of light and thirteen of darkness, and the "true" Kingdom Hearts disappeared into the darkness.
"However, the world was restored by the light within the hearts of children, as many individual worlds separated from each other. The remnants of the battlefield on which the Keyblade War took place became the Keyblade Graveyard, a scarred wasteland filled with the Keyblades of fallen warriors. The remaining Keyblade wielders resolved to protect the World from further destruction, becoming guardians of the world order.
"Prior to the release of the Heartless, the worlds were surrounded by barriers to prevent outside interference, making it impossible for different worlds to have contact. However, the arrival of the Heartless caused the barriers between the worlds to crumble and disappear, and some worlds were consumed by the eldritch horde. Gummi Blocks are pieces of these broken barriers.
"Those who travel between worlds are advised to avoid meddling in the affairs of other worlds and informing their inhabitants of the existence of other worlds. In order to maintain a balance of separation, several characters, notably Sora, Donald, and Goofy, magically alter their physical appearances in certain worlds to avoid standing out. For example, they take the forms of sea creatures in Atlantica, monsters in Halloween Town, jungle animals in Pride Lands, and computer A.I.s in Space Paranoids and The Grid." -- From the Kingdom Hearts WIki

Geography

A sea of stars, within which the remnants of different Worlds exist. There is a vast distance between each World. There are three parts: The Realm of Light, The Realm of Darkness, The Realm Between, and each of these realms have Worlds within them.

Fauna & Flora

Flora and fauna differ from world to world. The space between the planets is mostly barren. There are @heartless of many different kinds.
The most notable fauna is a giant whale named @Monstro who is known to eat @Gummi Ships if they fly too close to him.

Natural Resources

@Gummi blocks, pieces of the broken barriers that once protected worlds, are the most abundant natural resources. They are shards of stars, and are used to make Gummi Ships, which allow travelers to safely move from @world to world.

Type

Universe