Reisen Gorge

Reisen Gorge (ライセン) is a canyon that divides the North and South portions of Tortus. It runs anywhere from 1 kilometer deep at its more shallow ends, to 2 kilometers deep in certain places. It can span anywhere from 900 meters to 8 kilometers wide, depending on the area, and it runs all the way from the Gruen Desert in the west to the Sea of Trees in the east

It is used as an execution ground since magic can not be typically used inside of it, as well as an abundance of strong monsters that live down there. It is the place where Miledi Reisen's labyrinth and the exit to Oscar Orcus' labyrinth is located.

Trivia

 * Reisen Gorge is one of the few locations that has retained its name in both the Main series and Zero series timelines.