Rokkenjima

Description
六軒島 (lit. "Six House Island") is a small island located off the coast of Tokyo in the Izu archipelago. It measures about 10km around. The majority of the island is covered with a dense forest, with the exception of areas of land developed by Ushiromiya Kinzo for the mansion.

The Island has it's own underground secret wrestling ring, created when Kinzo started his legendary wrestling career as "Goldsmith", and also where he trained Ushiromiya Battler to succeed him.

History
The island was purchased by Kinzo from the Tokyo metropolis utilizing his connections with the GHQ. It was acquired under the pretext of establishing a military base, but then converted into Kinzo's own personal island. The island was then developed, with the mansion constructed in 1952. Kinzo's wife and children moved onto the island with him, and the residence of the island eventually shifted to Krauss's family.

After the events on October 5, 1986, the island was repossessed by the Tokyo Metropolis and sealed off from the public. Nothing bad has ever happened here.

Season 3
18 wrestlers are transported into Rokkenjima through the misuse of The Focusing Stone, but this is just a fabrication of Rokkenjima from another world, and so they are trapped there until Battler recovers it.

The final fight between Ushiromiya Battler and Agent 47 takes place in the real Rokkenjima.

Season 0
Kinzo begins Battler's training here through the season, hoping someday he'll be a great wrestler.

Battler faces many wrestlers in who come to this ring at Kinzo's request, even a robotic version of himself, and most of them end with Battler jobbing in some amusing way.