Which one is Level 11? I think it's the Forsaken Valley, but I'm not sure.
It is the Forsaken Valley.
On that note, how do you beat level 12 on Iron? No matter what I do, I always get overrun because it doesn't allow artillery and there's simply too many units. I've tried basically every mixture of towers, upgrades, abilities, placements, and whatever else and I always die at this one point, even though I'm fine up until then.