Abandon - A large, abandoned town square, absolutely destroyed by war as it is also full of radiation.
Showdown - A large fairground area with a large stage that a band would play on. This area is cleared out with blood on the ground and perfect for close quarters combat.
Whirlwind - An old airport in the midst of a tornado, fight through the mist and wind to destroy your enemies and leave their bodies to the whirlwind.
Inferno - A large forested area with trees that are burning faster than you are killing. Take refuge in the burning, wooden hut, trying to avoid all flames that attempt to devour you.

Location 12 - This area is rumored to be a wartorn Area 51. As helicopters lift off from the unknown area, you wake up in a surgical room, blood spattered everywhere. Survive against the unknown force.

There are two gametypes to play on Location 12. Survival, and Escape. Survival is normal zombies as you survive as long as you can. Escape, you have 20 minutes to complete a series of objectives before the Fighter Jets blow up the whole area. Now apparently, if you complete the objectives you're assigned, you can do an easter egg in Survival mode and you get to see some hidden cutscenes. Good luck.

I have heard that the bonus would be another weapon DLC, a weapon called the Thundershock, an apparent SPAS-12 kind of weapon with 12 shells in a mag, and it can hold 3 total mags. I have no further information.