I tried all possible way to make this 'very long trek' as short as I could but this is the way I ended up with.
Go back around (very long trek) to get to the other side of the closed door with icons.
You are already at the 4-way tower, right?
Then go to the right to go back across the bridge that you raised up at the very beginning of the game. You change to CD2 here.
Go forward as far as you can go. Pass the open doorway - do not turn left (you'll end up to the east bottom level of the walkway), go forward between cliff walls.
Up to the building, down the stairs (that has the tunnel/passage underneath to go to another place).
Forward to the bottom level of the North exit of the walkway tower.
Climb the ladder, turn around to exit the North top level exit of the walkway tower.
Go forward, down the ladder and see the revolving bridge. Change to CD3.
Go to the closed door with 2 icons and now see a ladder. <img border="0" title="" alt="[Confused]" src="confused.gif" /> <img border="0" title="" alt="[Confused]" src="confused.gif" />
Whew!!!! That tired me out just thinking about it.
If you still get lost, look at the map at the very beginning of the wt. Follow the blue line at the bottom, up the side of the map and see that it goes to the north door of the walkway building.
Good luck and holler, if you need me again.