Mirror Chamber

The Mirror Chamber is a location in. It is an ancient, open-air atrium located above the Arbiter's Grounds that houses not only the Sages, but the Mirror of Twilight and thus the only entrance to the Twilight Realm. Link cannot gain access to the Mirror Chamber until after he defeats Stallord, the boss of the Arbiter's Grounds.

The Mirror Chamber resembles the Roman Colosseum in structure, and boasts six, great equidistant spires that serve as symbolic insignias of the Sages that oversee the chamber. One of the spire tops is shattered, symbolizing the death of the Water Sage at the hands of Ganondorf.

History
Prior to the events of Twilight Princess, Ganondorf was put to trial by the Seven Sages in the Mirror Chamber. However, despite having been struck by the Sword of the Sages in an attempt to execute him, Ganondorf was able to break free of his Sage-given shackles using the Triforce of Power, killing the Sage of Water in the process. The Sages then quickly proceeded to send Ganondorf to the Twilight Realm via the Mirror of Twilight, located at the rear of the chamber.

When Link arrives at the Chamber, only a statue resembling the Goddess of Sand resides within, with no indication of the Mirror of Twilight or the large, black monolith that had chained Ganondorf in the past. After riding atop the statue and using the Spinner at the apex of the large structure, the statue itself dips into the sand, raising not only the black stone, but the Mirror of Twilight itself. Midna, however, realizes that only one-fourth of the Mirror is intact, and it is at this point that the Sages make their appearance and explain that Zant has fragmented the mirror with the help of Ganondorf's "mighty magic," not having been able to completely shatter it due to him being the false king of the Twilight Realm. The Sages then reveal the location of the three missing shards: Snowpeak, Sacred Grove, and the City in the Sky. Once the young hero and Midna succeed in gathering the three Mirror Shards, they return to the Mirror Chamber to reassemble the Mirror of Twilight and enter the Palace of Twilight to ultimately defeat Zant.

During the ending credits, Link, Princess Zelda and Midna gather at the Mirror Chamber to bid farewell to the Twilight Princess as she returns to her realm. However, just as she is about to depart, she sheds a tear and uses it to completely shatter the Mirror of Twilight, thus destroying the only connection between Hyrule and the Twilight Realm.