Hall of Origin

The Beginning Dimension is where the Legendary Pokémon Arseus resides.

The Beginning Dimension can only be accesed by a Nintendo event in which the player receives Heaven's Pipe. When the player goes to the top of Tengan Mountain (Spear Pillar), the game will ask you if you want to play Heaven's Pipe. When you say yes, a stairway will appear and Arseus wil be waiting at Level 80.