|Fortress of Solitude|
Superman IV: The Quest for Peace
The Fortress of Solitude is the place of solace and occasional headquarters for Superman in the Arctic.
The Fortress of Solitude is created by a crystal that Jor-El enclosed in Kal-El's spaceship. The crystal leads a teenage Clark Kent to an ice field where, after he throws it down, it melts into the ice and grows into a huge crystalline building, similar to the crystalline architecture native to the planet Krypton.
The Fortress contains numerous memory crystals that can be used to access Jor-El's artificial intelligence and holograms, interactive holographic recordings of Lara Lor-Van, and other Kryptonians, and a chamber that uses red sun radiation to strip Kryptonians of their super powers. The chamber was first used in Superman II when Superman willingly stepped into it in order to be with Lois Lane. After his powers were restored, he battles General Zod, Ursa and Non and tricks them into thinking they could force him to do it again, but he secretly switched the controls so they were depowered outside the chamber while he was safe inside of it.
In Superman II: The Richard Donner Cut, the Fortress is destroyed by Superman as its existence was revealed to Lex Luthor and Eve Teschmacher. However, Superman then turns back time, so technically the Fortress is completely undamaged, while General Zod, Ursa and Non are returned to the Phantom Zone.
In Superman Returns, Lex Luthor travels to the Fortress of Solitude, acquires information from Jor-El's artificial intelligence, and steals several crystals to further his plot. According to him, most people think the Fortress of Solitude is Superman's home, but he is aware that Kal-El lives among humans.