The tree of life, the axis mundi is the central point, the pole around which all revolves. The central point of the world is the point where stillness and movement are together. Movement is time, but stillness is eternity. Realizing how this moment of your life is actually a moment of eternity, and experiencing the eternal aspect of what you are doing in the temporal experience -- this is the mythological experience.
There is a mystery about rivers that draws us to them, for they rise from hidden places and travel by routes that are not always tomorrow where they might be today. Unlike a lake or sea, a river has a destination and there is something about the certainty with which it travels that makes it very soothing, particularly for those who've lost faith with where they're headed.