Infinity Tower is a location on the game Digimon Digital Card Battle. It is a large, black tower where various evil Digimon reside. It is taken over Analogman during the course of the game, and it is the last area opened up to the player.
Infinity Tower is a cilindrical structure that lifts itself towards the heavens. It is surrounded by a thick mist that prevents the penetration of sunlight. The tower itself is made of black metal, its walls covered in polygonal patterns. The insides are gloomy, lacking distinguishing features.
Infinity Tower is characterized by being inhabited by crooked Digimon who have lost their way. Most Digimon at Infinity Tower are inherently evil Digimon plotting crimes such as murder, kidnapping, bodily injury and general dominance over the whole Digital World. Most notably, Tuskmon, Phantomon, MegaSeadramon, MetalSeadramon, Piedmon, VenomMyotismon and Apokarimon can be seen roaming the Battle Café. It is implied that Digimon are bound to Infinity Tower by their evil ways; once Apokarimon lost any hate and will to fight, he could leave the tower to roam the Digital World.
As for the events of Digimon Digital Card Battle, it is implied that A opened a Back Dimension area on Infinity Tower, which allowed him to seize it and possess an unsuspecting VenomMyotismon. This particular Back Dimension was to be expanded over the Digital World. The dimension collapsed on itself after the protagonist defeated A in a card battle, which triggered a defense mechanism the security system disguised as Rosemon used to lock A into an infinite loop and cast him into the Deep Web.