Thanks everybody.
I am getting it put together for the contest and should have it submitted early next week.

The rooms that are sealed off have secret doors. In the virtual tabletop apps with fog of war revealing a wall that looks different is usually too much of a tell-tale sign to the players to search.. so I leave the wall looking like every other wall. If you look close at the floor leading into the glowing chamber you can see scratches in the floor and little piles of rubble from where the secret door opens.

-D