Hell's Gate

Hell's Gate (地獄門 (ヘルズ·ゲート) Heruzu Gēto) is a chaotic area of space located in Tokyo.

Overview
Hell's Gate appeared approximately ten years before the start of the series, bringing along with it a fake set of stars, as well as the appearance of Contractors and Dolls.

The Gate seems to have an effect on Contractors that get too close to it, as it makes them restless. Likewise, if a Regressor gets too close to the gate, he or she may regain their powers.

The Japanese government has built a massive wall around the gate to keep the public and other Contractors out. The Gate seems to be the subject of a lot of research from all different nations. PANDORA, a Hell's Gate research organization, operates in and around Hell's Gate.