Alright I made this map. Here's the link to the download, hopefully you guys
like it.
http://o0oo0.net16.net/daimonin/Forest%20of%20death.tar.gz

If you want me to I'll make a quest for it.

Definitely a good start

I have a couple of improvements for it:

Aesthetically, it may look better to also use the other type of cave wall to make it more varied so more realistic. Also, if you look in the masks tab you can add some of those to also make it look more real.

To make it actually work as well, all of the tiles with the on them need to be covered by a floor tile so in your underground dungeon you should use the floor tile "blocked" to blot them out. Also, with the corridors in your castle, you need them at least one tile thicker to be able to walk down them as at the minute the path is obstructed by the other wall.

The maze looks very good - although again maybe so masks or tree variation?

Other than it, good job You've got the basics sorted and most of the technical aspects.