Genbu

The turtle's shell, the "island", has an accumulation of plant life that has grown on it. Despite being described by the Great Toad Sage as a paradise, it is anything but that to humans, with signs of death and battle everywhere and large, ferocious animals populating the island. The Falls of Truth can also be found on the island. The island was protected by a Giant Squid, which attacked anything that approached, and a high-level barrier technique. In addition, the island can move, making it impossible to find without air reconnaissance. The turtle itself is one of — if not the largest — creature in the series, easily surpassing the nine tailed beasts and the Sannin's respective larger summons, while rivalling the Ten-Tails, in size. It is mostly grey in colour, with spikes protruding from its shell and with a blue underbelly. Its shell is extremely sturdy, being able to withstand attacks of powerful techniques and can even house the tailed beasts, though it is implied that its underbelly is less so, but still strong enough to handle even one of Deidara's explosions without sustaining any damage.

A and Killer B trained on the island when they were younger. While there, B tamed and befriended all the animals on the island. He now has a vacation home there. When the Fourth Shinobi World War begins, the Shinobi Alliance sends B and Naruto Uzumaki, the only two remaining jinchūriki, to the island to be hidden from Akatsuki.