Training Cave

The Training Cave.

The Training Cave (修練の洞窟, Shūren no Dōkutsu) is a location in an undisclosed area previously used by the Akatsuki. Most of its structures are built into a mountain side, and at its entrance stands an elaborate torrii with a bridge over a small lake. It was here that Tobi alongside Zetsu carried out the test for the Limited Tsukuyomi: a prototype for the Infinite Tsukuyomi. After Tobi used the Telescope Technique to uncover what was in Naruto Uzumaki's heart, he and the other "Akatsuki members" now begin the Limited Tsukuyomi experiment.