The Streams of Destiny is the domain of The Vision. She, along with her Scions and descendants, use it as a means of transportation. It is described as a world with small streams that branch and merge as far as the eye can see, glittering sand, and skies that constantly shift color, usually lingering on shades of blue.
If someone touches the liquid in these Streams, they will see random glimpses of the future. It is unknown what happens when someone drinks it, but it is speculated that they would go brain dead from information overload.
There may be other, unexplored parts of the Domain, aside from the Streams.