Orb Dimension
Ruled By: No One
The Orb Dimension is found within Doctor Strange's Orb of Agamotto. It is a dimension of unreality where Doctor Strange's memories of the past make a kind of Wonderland realm, (as in "Alice In Wonderland") but it is populated by characters and creatures whom he knows or has feared (super-powered heroes, villains, friends, physical manifestations of famine, disease, etc.)
Magic operates as normal and some spells, such as Illusions and Confusion, are especially potent. Entrance into the world is through the Orb itself, or through the Eye of Agamotto within Doctor Strange's amulet. One must venture through the unreal lands to the center of the Orb before finding the exit out of the Orb Dimension. It is not easy to escape, Doctor Strange trapped Silver Dagger inside the Orb of Agamotto for a long time. Silver Dagger escaped, but was captured and re-imprisoned by Strange.
It is possible that every mystical orb has its own dimension inside.