Riverrise is a fictional spring from Paul Stewart's The Edge Chronicles.
Riverrise is the legendary source of the Edgewater River. The spring is located on a sharp summit of rock at "The black heart of the Deepwoods", and has a sacred garden at the very top. The garden was once home to Kobold the Wise, a great leader of the various tribes of the ancient Deepwoods. The legend that surrounds it is called The Myth of Riverrise
The Deepwoods was once a chaotic place inhabited by a thousand tribes. They were always fighting and warring among themselves until a man named Kobold the Wise united them under the banner of the Snake and Trident, and an era of peace began on the Edge. Kobold took up residence at Riverrise, and oversaw the invention of the written word. The Time of Enlightenment ended when Kobold grew old, and chaos descended once more. To try and keep the peace, the representatives of the thousand tribes gathered at Riverrise and held counsel together. They looked to the weary form of Kobold the Wise for help, but all he said was, Lo, the Mother Storm returns. Her madness shall be our madness. Prepare yourselves, for time is short. When Kobold the Wise died, the thousand tribes split up, and the whereabouts of Riverrise was lost.
In the final book of the Twig trilogy, the Mother Storm was returning to rejuvenate the waters of Riverrise, as it had done for aeons. All would have been well, if not for the fact that the floating city of Sanctaphrax was in its way this time. The Mother Storm would waste its energy destroying Sanctaphrax, and the drought would wipe out all life on the Edge. Twig Vergenix had been told of this, but he had lost his memory when an explosion destroyed his ship, the Edgedancer. Twig and his apprentice, Cowlquape, searched for his crewmember Maugin, hoping that she might have remembered about the impending disaster. The search led them to Riverrise, where they found her. She remembered what Quintinius Vergenix had said before he ceased to exist, and spurred Twig's memory - the Mother Storm would strike at dawn over Riverrise, or Midnight over Sanctaphrax. There was not time to walk back to Sanctaphrax and cut the Great Anchor Chain, so Twig and Cowlquape were tied to a burning lufwood tree. Lufwood becomes buoyant when it is burned, so Twig and Cowlquape were fired to Sanctaphrax. The process is called sky-firing, and would have blasted them into Open Sky had they not aimed it at Sanctaphrax. Cowlquape cut the Anchor Chain, and Sanctaphrax floated away, allowing the Mother Storm to continue unimpeded to Riverrise.