Not sure if this is a Terraforged issue or a dungeon crawler issue but dungeons are spawning completely underground and aren't visible from the surface. Not all dungeons are doing this but alot are when they generate. And since I turned down the spawn chance a little bit it's making them mostly impossible to find.

Edit: Dungeons are meant to spawn underground (Duh :P), and you probably understood what I meant from the screenshot.. For clarity though I should have said the towers that you find to enter the dungeons, are spawning underground with the terraforged mod.