|Fortress of Solitude|
Superman IV: The Quest for Peace
The Fortress of Solitude is the place of solace and occasional headquarters for Superman.
The Fortress of Solitude is created by a crystal that Jor-El enclosed in Superman'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.
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.