(secret underground Torpedo Plant)

(secret underground V2 rocket plant)

(secret underground oxygen plant)

(secret underground Me-262 plant)

(secret underground oil refinery)

(secret underground electric tubes plant)

(secret underground propeller plant)

(secret underground ammunition plant)

(secret underground Heinkel aircraft plant)

(secret underground tank engine plant)

(secret underground tank plant)

(secret underground aircraft plant)

(secret underground oil-refinery)