Batman Arkham City - Harley Queen Balloon Guide [The Party's Over]
If you bought the DLC "La vendetta on the Harley Queen" per Batman Arkham City you may need some help finding all the balloons and unlock the achievement / trophy:
The party is over - Destroy all of Harley's balloons
The balloons to destroy are 30 in total and in the following video you can see the exact position of each of them. Here it is all for you!