Kamui's Dimension

Other Dimension is an alternate space which only enter with Space-Time Ninjutsu. It is unknown all of space-time ninjutsus are connected but Kakashi's Kamui and Tobi's Space-Time Migration have same other dimension. Kakashi used this as an advantage in the battle between them.

Appearance
There are a lot of white coloured largely composed rectangular prisms and they have different lengths. And all of place is completely dark.

History
It seemed just one time. Tobi sent Karin and Sasuke to this dimension for healing Sasuke after battle with 5 Kages.