Divine Temple

The Ark Cradle seen during the dimension rift.

The Ark Cradle is ZONE's fortress in Yu-Gi-Oh! 5D's.

After being transported through a wormhole via Infinity, Bruno and Yusei Fudo entered a distorted dimension and saw this structure. Yusei saw a vision of his father, Dr. Fudo.

He advised Yusei not to get close to the structure, which he described as the the last Ener-D and the place which leads to the destruction of mankind.

Once Yusei and Bruno returned to their own world, the structure was visible in the sky through a hole showing its dimension. The hole was only visible to the Signers and Team Ragnarok.

Strangely after Yusei's intensive battle against Taro Yamashita, a part of the island is seen trasspasing into the real world. Strangely at the time this occurred, another part of the Infinity Circuit had lit up before.

Before Team 5D's duel against Team New World, Primo, Jakob and Lester reveal that the island is really their God's fortress and that it will show up when they win the World Racing Grand Prix. But when that happens New Domino City will be destroyed and the world will change.

Only those with the Mark of the Dragon or the Rune Eye can see Ark Cradle, but if someone is in physical contact with one of these people, they will also be able to see the fortress in the sky.

The Ark Cradle in the sky is similar to the Pyramid which only Atem can see in Ancient Egypt.

The Ark Cradle is possibly another reference to Norse mythology in this season, as it is shown surrounded by red energy and is upside down (an "under-world"). In Norse mythology, the army of giants (Like the Machine Emperors) that challenged the gods were lead by a giant that was the guardian of a fiery "underworld" realm.