Dreamscape

From Kokorodatabase

The world created by an individual's dreams, this has no set appearance, based only on the dreamer's mood and feelings at the time. Only Baku and dreamsages can enter this realm, and for good reason- not only can objects be taken out of dreams, but any monsters there are tangible, and can deal considerable damage.

There is also, somewhere, a kingdom, ruled by the Queen of the Dreamworld.