Oz

Oz is the world where beings like the Wicked Witch reside currently not much is known about it. However it has been stated that witches and flying monkeys reside there, and that it's a part of the fairy world.

Access and location
There are several known ways to access Oz. Most of them rely on weather disturbances that are vortices.
 * Tornadoes
 * Eye of a Hurricane
 * Whirlpool
 * the Key