Territory the AI tacked on when it enlarged the battlefield, populated with recycled mobs and no quests.
Carl's hunt takes place at the very edge of the map, in the "new" area added when The AI made the playing field larger. Reports from other teams say the mobs in here can be pretty much anything: there is no rhyme or reason and no quests, much like the first floor, because the AI is recycling mobs from all the previous floors, changing them up a bit and strengthening them to be level appropriate.
The evidence piles up quickly — Imani's team fought Chilly Goats from the first floor, Jurgen's group fought Danger Dingo-Riding Kobolds from the second, and Carl's party faces a Rolling Battle Formation Ball that is plainly a riff on the first floor's Ball of Swine. Oddly, the ball isn't flagged as a boss despite being larger than the borough-boss original. A few dozen mob incursions keep popping up like cockroaches out of this territory, and the army has spread the hunting duties across volunteer squads, mixing newcomers with active crawlers so everyone can grind. At the far edge sits the buried Saferoom Imani's team found.
Dense forest of trees and vines at the very edge of the map, scarred with long circular paths of destruction where mob formations have rolled through.
The frontier hunting ground where the army grinds levels during the ceasefire.