The Vortex is home of the animal kingdom in Japan. None of the humans know about this sacred island except Dr. Deller. The animal kingdom is AETA's weapon capitol.
The Vortex is the connection to The Wolves. They originally owned it. The roots under the trees all connect to the AETA spirit tree. Mother Vortex also happens to be the largest tree in the Vortex. She uses her power to protect the island.
The Quads of Pain's home rests in the vortex. Every Saturday the Quads go to protect it and live their lives.