Custom made padded add-on dungeon.

To use the trapdoor just stand on one of the two spots it has, your avatar will seem to disappear. Now make a full zoom in to your avatar (using the mouse wheel or moving the mouse forward keeping the left button pressed) it will let you see a close view of your avatar. At this point just click on one of the secret room spots to move your avatar.

Also, in order for your furniture to stay in the dungeon, you should place them on the main room nodes and drag them in place.

As always, try before you buy.