Setting
Although it may appear as a void of white, in actuality it is a tall, slender tower with a wide, spindly castle-like structure at it's top. Though, the tower might contain a sort of pocket dimension similar to Dungeon Gateways.
From the World Map: It looks like this.
Cosmos nodded. "Yes, Chaos's ranks are large, and you must watch out for him, hsi warriors, and manikins."