Oh nice, a military base for each special type. A quest to destroy each to get the traders back up and running.
Nuclear = Rad Zombies
Explosives depot = Demo
Hospital = Screamers
Science Lab = Wights
Animal Lab = Dogs , Vultures
Final biggest underground base = all horde night zombie spawning
These bases spread out in the map, one per Biome? It’s destruction leads to lower their spawning rate during horde night. Possible rewards skill books or ability points.