The 18th Barrier is a vast defensive wall overseen by the IGO's Bureau of Defence and it is the safest one of the land routes into the Gourmet World. It is stationed on Zabel Island, a small island that is part of the grander Area 7, one of the major regions of Gourmet World.
The barrier is under the supervision of surveillance chief Elboh, and he and his guards are charged with protecting the Human World from beasts that could climb up the Waterfall Basin of Life to menace humankind.
Sunny suggested this place to Toriko when he wanted to test his strength at Gourmet World.