I have found a wall that has a very suspicious effect on it. If you head DOWN the stair leading to the Smough and Ornstein fight, and turn LEFT before the doorway that takes you to the actual wall with the Sentinels, the floor in front of the wall has a very strange white glow at the base of the wall that the other side mysteriously lacks.
Now, it's not a typical invisible wall, and I doubt anything will come of it, but I know there has been some hints that a special invisible wall still exists in hiding out there.
Now, it's not a typical invisible wall, and I doubt anything will come of it, but I know there has been some hints that a special invisible wall still exists in hiding out there.