How to find Building 21 Location and Keycard in Modern Warfare 2 DMZ
Building 21 is an unknown location in Modern Warfare 2 DMZ mode that will be available with the mid-season update. You can unlock Building 21 Location in MW 2 with our guide here. Modern Warfare 2 Season 1 reloaded update will bring a new unknown location named Building 21 to the DMZ mode. Modern Warfare …