Like a picture postcard of a vacation, when humanity began to put more faith in cold hard facts (and cold hard iron) over whim and fancy, the mythic parts of the world branched off to an overlapping level of reality called The Dreaming.
Initially, this may have served as a buffer zone between Arcadia and the mundane world during the Sundering, connected to both by way of trods. When the Shattering took place, all paths to Arcadia itself were closed off and only the very rare path to the Dreaming remained. Fortunately this still allowed a slow trickle of Glamour to reach the mundane world. Only during the Resurgence were the trods between the Dreaming and the mundane world re-opened.
The Dreaming might better called "The Dreamings" (plural) since it is divided into three layers: The Near Dreaming, the Far Dreaming, and the Deep Dreaming.
The Dreaming is a universe unto its own. It is said that any and all things may be found there, if one knows how to look. Given this infinite tableau, many of the commoner kith fear to return to this place that was once most natural to them. Others, however, are now rediscovering their lost legacy. Most of these fae do not travel beyond the Near Dreaming. The only way for most changelings to enter the Dreaming is by entering a trod. Although the Dreaming is a place of infinite expanse and diversity, it is generally agreed that it can be divided into three major realms.
The Near Dreaming is that which most conforms to the mundane, "real," world. It often (though not always) mimics it in such major aspects as geography. Human-made constructs (such as buildings) may also have their Near Dreaming counterparts, but more likely not. As a rule, human artifacts that are imbued with a great deal of imagination are more real in the Near Dreaming (i.e., a cathedral would leave more of an impression than an O'Tolley's restaurant). In the Dream- ing, a creative work, such as a book or painting, may even be alive. Most freeholds are situated in the Near Dreaming. It is also here that the nature of a kingdom's ruler has the most effect on the land. The Silver Path begins to fail at the far edges of this realm.
The first is the closest to the mundane world and often reflects it, albeit in a more fanciful way; a factory might be expressed as a huge clockwork mechanism, a bustling mall as an open-air forum, an airport as a landing pad for dragons and air-ships. When in the Near Dreaming, a changeling finds their fae mien more 'real' than their mortal seeming in the reverse of how things are normally (where the mortal mien has precedence and the fae seeming almost seems like a daydream). In Freudian terms, this would be the dreams of the Superego.
The Far Dreaming is mostly beyond the authority of the sidhe nobility. Some fae occasionally come here to escape the nobility. This is dangerous, however, because the sidhe know the Far Dreaming better than any other kith. The Far Dreaming can be tumultuous, even cataclysmic; or it can be placid and benign. Fae Arts work well here, but the chaotic nature of the Far Dreaming makes permanent residence here almost impossible for all but the most powerful of Kithain or chimera. The Silver Path exists in the Far Dreaming, but is far less reliable — only the most powerful trods extend this far into the Dreaming.
The Far Dreaming is more the dreams of the Ego, with little matching landscape to the mundane world. Not only is the fae mien of a Changeling more 'real' here, but it is almost a caricature of how it normally would be (for better or for worse).
The Deep Dreaming is poorly understood by earth-bound fae (including the sidhe) for good reason. The Deep Dreaming may contain such paradises as Arcadia, but these exist side by side with nightmare realms of unimaginable cruelty. To explore the Deep Dreaming as Duke Asterlan did is to be lost forever. Even members of the Crystal Circle travel here but rarely. The Deep Dreaming is said to connect to other realms (such as the Umbra). In the Deep Dreaming the Silver Path is something of a joke among local chimera. There are only a handful of trods that extend this far — and even then one must know the arcane secrets which allow their doors to be opened.
The Deep Dreaming is more the dreams of the Id and is largely defined by the opinions of the viewer. For this reason, few ever return from the Deep Dreaming due to a false exit appearing to lead one to a false destination when one wishes to leave.