The way i understand it dreams are a hatch through which we can explore all sorts of different things. We can explore ideas, memories, our own psychology, we can explore communal abstract collective things too, we can meet the dead, experience the future, we can explore real places in the real physical world, we can also explore real places that we can not access via waking physical world. We can meet other real beings that have other independent lives of their own. We can meet dream characters that are merely projections of our own subconcious. Learning how to navigate these experiences and knowing exactly what is what takes a lot of experience.To say there is a dream realm is an over simplification. Dreaming is a hatch to inifinity.Thats a big big place.Thats a cool dream experience you had about the museum Azolus though.