After playing a bit with Dungeon Designer 3 I began work on a dungeon for my D&D campaign. After making a somewhat complex cave I realized I had way too much space left. As the cave fits in on a larger map and took quite a while to make, I'd really rather not have to make it all over again.

So I'm hoping you guys know a way I can cut off the space I don't need, as I can't get an image of the cave in good quality since the whole image is so big.