Rising Falls

The Rising Falls is a location from Kingdom Hearts at the very entrance to what remains of Hollow Bastion that sets the tone of the world with a broad vista of ice, water upon which one might, strangely enough, walk, and the view of a majestic, if twisted, castle in the distance against a rosy, twilight sky. The mechanism by which Sora is able to walk on water in Hollow Bastion is never actually explored, though his first chance to do so is upon his entrance into this world.

The Rising Falls itself is a water-filled valley in the shadows of the castle in which some ruins of either fallen parts of the castle itself or pieces of the town that ostensibly once stood there may be found. It appears to be a reverse-rift in a large body of water from which the water actually rises and flows into the large reservoir that appears to surround what remains of Hollow Bastion. If Sora jumps into a bubble floating above the water, he can travel underneath it for a few seconds. Icy platforms raise and lower themselves in the air. It is here where Riku first arrives after giving into the darkness at Destiny Islands. It is also here that Riku confronts the Beast. It's also the same place where Riku took the Keyblade away from sora, stating that his part was over.

The Rising Falls were not seen or spoke of in Kingdom Hearts II. So, it is possible that they were manipulated by the powers of darkness to rise, in an attempt to either slow down or confuse their foes.

Trivia

 * During the GMV openining of Kingdom Hearts II when it shows Sora, Donald, and Goofy hopping from platform to platform in the Rising Falls, it shows them defeating Heartless as they travel, but there are no enemies in this portion of Hollow Bastion, only treasure chests, bubbles, and a save point.
 * The name 'Rising Falls' is in itself paradoxical, as the terms 'fall' and 'rise' contradict one another.