uh, that's for the upgraded AMMO once you've pack-a-punched the weapon. you gotta use the pack-a-punch machine before you can have access to the ammo on the wall. the wall weapons pretty much suck though, so it's only worth getting if you happen to be camping in a spot that's close enough for you to regularly go back to and refill your ammo.
in the first level der reise all there is, is the weapons on the wall. you can by ammo foff he wall for the weapon you have equipped.
in the zombie factory level, the third one, after you link all the teleporters, there are 3, the pack a punch machine opens and you get an upgraded version of the weapon
the mystery box appears int he 2nd or 3rd zombie level and you get a random weapon, including a ray gun, and the wunderwaffle which is like a chain lightening gun. also there is a monkey bomb which is like a grenade that the zombies will flock to and watch for a 15-20 secs.
Uhh Der Riese isn't the first zombie map, Nacht Der Untoten is, Der Riese is the Last map in WAW. All zombie maps have featured the Mystery box as well. It amazes me you calling people "noobies" when your information is far from correct. Also these maps are only available via hardened edition for now, so i assume they are referring to the new maps. To answer the TC's question though, it depends on what map.
In the Zombie theater, once you've made it to the theater room, and have activated the power, step into the teleporter and follow the cable into the original starting room. Now step on the receiving plate, press square, and now it is active. Return to the teleporter and teleport to the screening room where you can PAP weapons for 5000 points. In five, once youve made it to the third level activate the power, return to the second floor, and activate all the Defcon switches around the room. The portal has now opened to the PAP room, and it is located near the second elevator.
anyway, depending onn the map you are playing (im going to assum kin der untoten) what you have to do is take the teleporter for a joy ride (turn on power, link it with mainframe, buy for X ammount of points)
you will go into this room with a mahcine that allows you to upgrade your weapon (it costs 5000 points to do so), then when you buy ammo for that weapon off the wall it will cost you 4500 points
if you need anymore zombie help just ask
^the post above mine has a 75% chance of being false or misleading, why? because this is gamefaqs....