MW2's "Hidden" Spec Ops mission has an indescribable atmosphere. I recently went flying around out-of-bounds for some good pictures, I couldn't stop thinking "this would make a perfect zombies map." Most of the original "All Ghillied Up" mission from COD4 is intact in MW2, just scaled down, with the second half placed out-of-bounds and made barren. Really feels like you're alone in the world. It's a perfect layout I think, and I wonder if it's ever been done as a custom map. Here's what I imagine:
 
Starting area in the playground, go up fire escape to the right and clear debris, leads through second floor apartment and out into the alley

 
 
Alley's wide open, has wall weapons, path leads down the street to a shop entrance connected to a mall

 

 
 
Shop is small and gross but has perk, debris opens exit into a stairwell leading to the mall

 

 
 
Mall has multiple floors, narrow catwalk up top. Perks would make like old broken vending machines. Clear view of the outside.

 

 

 
Mall opens up to spacial lot, huge open space, probably with tanks and debris scattered to make training harder. Maybe restricted to the end of the grass patch out in front

 

 
 
 
That's all I got. If by some miracle we got a WAW port of this map, it'd basically make itself. I can show more screenshots.
I couldn't describe a more perfect map for zombies, with the varying room sizes, the color and lifelessness of it all, it's a shame this map is only playable in the MW gamemodes.
Just thought it'd be worth making an appreciation post. Hope someone feels similarly