Dark Carnival

Dark Carnival is the second campaign of Left 4 Dead 2, that takes place in a Whispering Oaks carnival. This campaign brings unique situations to Left 4 Dead 2. One situation described by the writer was that how weird it would be when the merry-go-round starts while you're fighting an Infected horde.

Trivia

 * This level looks very similar to the 2009 movie Zombieland, that has four survivors fighting zombies in an amusement park.
 * As seen in a screenshot for Dark Carnival, it seems that there is a new form of Common Infected for this campaign. It is, what looks like, an Infected clown.