Another fan labor effort, The Elder Scrolls Renewal Project, has been working on remastering Morrowind to run as add-ons for later games in The Elder Scrolls franchise (as Morroblivion for Oblivion, and Skywind for Skyrim). The project is also working on a remaster of Oblivion to run within Skyrim (Under the name Skyblivion).
The gates generate a random plane of oblivion along with a random sigil stone. Go through the tower all the way to the top, till you reach the sigil stone. Simply save the game before the stone spawns and you can re-randomize the stone by re-loading the game, if it's not to your liking. 781b155fdc