Can someone tell me how to get to the room that has the stone so I can close this gate? I'm in the correct tower, and see on my map the door to go thru that has the stone, but my problem is, I can't get to the door. I keep going thru all the other doors and bypassing the sig... or san... door. I've been to all the walk thru's but nothing that details the route.

That should be Random Oblivion World 4 You have to go up to the top of both of the side towers and click on a switch in each. That extends a bridge between the side towers to the main tower. Walk across the bridge to the main tower, and then you can get all the way up.

What SubRosa said, but when you have extended the second bridge you have to go down till you find yourself in the Anguish Shrine. there are three doors exiting it, you want the middle one to get to the Brooding Fortress. When you get there go up and you will find the Sigil Stone at the top.