Heart Gold and Soul Silver: Battle Hall
The Battle Hall is located at the northwest corner of the Battle Frontier. Talk to the worker in the green hat to enter a Single or Double Battle challenge. Talk to the worker in the red hat to enter a Multi Battle with a friend wirelessly.
In the Battle Hall you only choose one Pokemon for Single Battles, or two Pokemon for Double Battles. Unlike other areas of the Battle Frontier, you're Pokemon's level is not changed in the matches. Each round you choose a type of Pokemon you want to fight. After you win a match, the next Pokemon you face of that type will be a higher level.
You are awarded 1 Battle Point after 10 wins in a row.
Make sure to talk with the lady in a green hat facing south to get rewarded additional Battle Points for your record streaks.