The Sinnoh Battle Frontier is only exclusive for Pokemon Platinum. After defeating the Elite Four and tag teaming with your Rival to defeat Volkner and Flint, you gain access to the Sinnoh Battle Frontier. The symbol for this Battle Frontier is a pentagon with a large dot in the edges. These indicate the Battle Facilities: the Battle Tower, the Battle Arcade, the Battle Castle, the Battle Hall, and the Battle Factory. Like in Emerald's Battle Frontier, each facility is led by a Frontier Brain.
Battle tower Palmer
Battle Tower
The Battle Tower is the most standard of the facilities in Sinnoh. It is a standard 3-on-3 battle. The more wins you get, the harder the opponents get. The Frontier Brain in the Battle Tower is Palmer. And yes, it is really hard.
Arcade star Dahlia
Battle Arcade
The Battle Arcade is a new challenge. It is a standard 3-on-3 battle, but there is a catch. Prior to battling an opponent, the player must spin and stop a gameboard via the touch screen. The space that the player lands on determines the effects of the battle. The effects can affect the player, the opponent, or both; depending on which space they landed. The more wins you get, the harder your opponents get and the faster the board goes. The Arcade Star/Frontier Brain is Dahlia
left to right left,Darach right,Kaitlin
Battle Castle
You start with 10 Castle Points. Avoid damage to add to this. Pick pokemon with high HP to get easy points. The leader is Darach
Battle hall argentina
Battle Hall
You choose the type of your opponents. Using Sableye or Spiritomb is effective, because they don't suffer from type weaknesses. Every time you beat a type, their rank goes up. This makes them smarter have a higher level, and higher stats. After your 5th and 17th sets you fight Argenta
battle factory thorton
Battle Factory
You receive random pokemon. You must fight your opponent with these pokemon. You get hints about your opponent's pokemon. As you progress, you receive more faint clues of the opponent. The Factory Head is Thorton.