Pokémon Black 2 & White 2 introduces a brand new feature never before seen in Pokémon games. While previously, the Unova region was far away from previous regions preventing characters and Pokémon being there, the new games allow for more to return and introduce the special Pokémon World Tournament.
Located south of Driftveil City within the Unova Region, there is a tournament building where you can go to do these battles. The battles seem to be organised by the Sinnoh Champion Cynthia. In it, you will face up against numerous trainers, where if you beat them, you can get to the next round. However, the trainers within the tournament are a bit different to normal trainers.
Like the Battle facilities, these work in Single battles and Double battles as well as potentially other different kinds of battles.
When you first enter, based on the story, it only has one facility open to you. However, more open up over time