I made this in 3 hours after I made my day from COD.

I put the signs in the building, so that wont get you going crazy.
You must use Too many items mod to play this or I can guarantee that the creepers is going to kill your a** when you spawn them. This is a no cheat mode map.

There are two levers, one is the lava lever and the other one is the spawn lever.
First put zombies, creepers etc into the spawn box(the roof) then go down to the lever room, and pull the spawn lever and make sure the lava lever is turn off so that you can kill them with FIRE. kinda like first turn off then turn on, easy. There is also a crater outside about 20 blocks far to the east and a room underground.

Schematic only at the moment. World seed will be up tomorrow

-Proartyom