Call of Duty: Black Ops

Discovery - Discovery is set at an abandoned arctic research station.  The graphical style comes from the missions in the same location, but this is not a map "chopped" from the single player campaign.  This level is on the large side of what the game calls "Medium" and offers interesting gameplay.  There are two main sides with a ravine in the middle.  The ravine has several ways to cross, but also can be fallen into for a "Mistakes were made" suicide.  On each side of the ravine are several buildings.  The buildings in Discovery are wide open, and while they provide some great vantage points, they all have several access points as well.  Most notably, much of the map has high/low pathways and structures, helping to mix up gameplay and make the map feel larger.  Graphically, the aurora borealis effect is stunning.

Stadium - Stadium takes place outside a hockey stadium.  Unfortunately, huge potential is missed as the ice rink itself is almost entirely off limits.  Instead, you play primarily in the plaza outside.  Although the game lists Stadium as "Medium" in size, it is by far the smallest of the expansion maps.  It isn't quite a Nuketown or Shipment map, but it is fairly close.  The graphics are actually pretty bland, there is a lot of poured concrete and muted colors.  Stadium also has some prime camping spots, and can get a little hectic with explosives and kill streaks. Some players love this, but it can be very frustrating, and at times it can be hard to spawn in.

Kowloon - Kowloon recreates the rooftop escape from the story.  Kowloon is a difficult map to describe.  There are buildings with windows and stairs everywhere, which would make it seem like a camper heaven, but actually the map flows well.  Problems exist in that it can turn into a corridor style level a la early PSX and even N64 FPS games, and therefore rapid fire SMGs tend to dominate.  A major strength is that the map is easy enough to understand, after a few minutes you know which side is which and how to move across the map, however even after playing many games I still find new routes to take, a new ledge to hop on, a new window to climb through.  Kowloon is rainy, which is a nice effect, and has a low flying jumbo jet at the start of each round.  Kowloon also has two ziplines players can ride, but doing so is more of a gimmick as they almost always end in death.

Berlin Wall - The final map is Berlin Wall, which takes place at, you guessed it, the Berlin Wall.  The area between the wall is open, however stepping into it causes auto turrets to kill the offending player.  This is by far the worst map in of the set.  The choke points can easily become camped, and the way the buildings overlook the same choke points mean camping runs rampant.  The graphics are also fairly drab, and there is little to make the map wild or crazy.  Unlike Nuketown, or even Stadium, where they at least put in unique background features, Berlin Wall instead just looks like a part of any WWII FPS.  Objective based games also play poorly due to the choke points of the map layout.

The Zombie Map

Ascension - Although I am not fully up to speed with the developing Nazi Zombie story, Ascension takes place in a secret research facility.  Some of the gameplay tweaks are the lack of color until you turn on the power, and the ambient traps.  There are certain parts of the level that move on their own, killing players or Zombies who get in the way.  Ascension has some wide open areas as well, which I personally think make the Zombie mode more playable.