Void Junction

"This article is about the location. For the Season 3 episode, see The Void Junction (episode)." The Void Junction (無界閣, Mukaikaku "Chamber on the Boundary of Nothingness") is an unnatural realm located in the Labyrinth of Darkness in the Demon Spine Mountains.

Story
"The Labyrinth of Darkness, once a powerful dimension that connects space and time with tunnels, has been thoroughly renovated with magical power from the Demon World. The Void Junction is an extremely unstable area that does not belong to any spacetime."