Dark Jungles and Utopic Highlands are the dreaming landscapes of what has already occurred in our physical reality. We keep connecting in dreams to them because there is something not integrated that still resonates with our present reality, be it because of its magnificence or atrocity. In a way, we can say that a piece of our Soul remains stranded there, and we continue dreaming with it until we integrate the experience or choose to dream a better dream.
Dreamwalkers and conscious dreamers can visit ancient civilizations in these lands, even if they are unrelated to their personal history.
On the other hand, Time Rivers are within the Dreaming Landscapes of What Could Be; it is the land of collective and personal potentials, not only of the future but also of the past, of what could have happened –we may dream with alternate branches of the past that did not materialize on Earth.
Here we dream of the potential past or future of this timeline or other timelines; we also encounter ourselves in the potential past or future of our current lifetime, and we can dream with subsequent incarnations, too. As stated in The Dreaming Landscapes, one conscious human dreaming in this landscape can affect our collective future here, on Earth.
Journeys to the Time Rivers in the waking state are called Journeys to the Light1, those junctures in time where our personal story could have been different. Exploring what could have been is a healing technique because it illuminates why an alternate path was not chosen.
It is not easy to retrieve memories of these potentials, even for advanced dreamers; up there, the mind does not work that well, although it is not impossible.