Even the completely oblivious can't help but notice the large amount of grey in the lower right corner. The passage there has never been explored!
There are also two doors that have never been opened and probably won't be - one is off the evil priest's chamber and the other off the throne room of the "mad king."
|The green areas represent exits/entrances.|
I also noticed that there really aren't that many traps. My perception must have been skewed by the fact that multiple PCs have died in the pit trap just beyond room 17.
Dungeonographer has some limitations, such as not having a symbol for a one way secret door, covered pits, or any symbol for an exit to the surface world.
Still, for free, it's a great little program and it does just what it sets out to do. Both it and Hexographer have the added bonus that they run on my netbook - on which I'm running SimplyMEPIS as my OS.