Twilight Realm

The Twilight Realm is location from The Legend of Zelda: Twilight Princess. The Twilight Realm is another dimension. The Realm is home to the Twili race and is ruled by a king or queen. The Realm is lighted and protected by the sacred Sols, orbs containing the power of Light. Apparently, it has gods of its own. When the light of the Sols enters the Master Sword, Midna says it is because the gods of the realm have blessed it.

The realm is covered with an abyss of twilit clouds, and has black buildings everywhere. They float above nothing despite a clear presence of gravity, giving another hint of advanced technology. On a black plated rock is a palace square, where sols rightfully lie, and where the citizens of the twilight realm spend their time.

Origins
In the early history of Hyrule, there was a war fought over the power located in the Sacred Realm, the Triforce. A tribe attempted to steal the Triforce, and the three goddesses, Din, Nayru, and Farore, banished these people to the Twilight Realm. The only link connecting Hyrule and the Twilight Realm was the Mirror of Twilight which is partially destroyed by Zant but not completely as only the true ruler of the Twilight Realm can destroy it completely. The tribe banished to the Twilight Realm eventually became the Twili.

Attack on Hyrule
Zant was to be elected Twilight King, but he was passed over, causing him to go insane. It was then Ganondorf's spirit, who was banished to the Twilight Realm after murdering one of the Ancient Sages after escaping execution at the Arbiter's Grounds, entered his body and used him to gain access to Hyrule, and giving him sorcerer's powers and kinghood. Zant proceeded to merge the Twilight Realm with Hyrule and turning the Twili into shadow beings. The end result of the merge was Twilight.

Attack on the Palace of Twilight
Link, who was the hero chosen by the Goddesses, warped himself into the Twilight Realm through the use of the Mirror of Twilight to confront Zant. He restored the power of the Sols to the realm, which blotted out the darkness dwelling inside the Twili. The power of the Sols were transferred into the Master Sword, which gave it the power to blot out the darkness, and making Link the Hero of Twilight. In a final confrontation with Zant, he was assassinated by Midna, who was the Twilight Princess before her throne was usurped from her, by the use of the Fused Shadows. Unfortunately, having Ganondorf's power, he had immortality. But he permanently died when Ganondorf was defeated. After that, Midna returned to the Twilight Realm and presumably took her rightful place as its ruler.