Fortress of Solitude

The Fortress of Solitude is Clark Kent's sanctuary in the Arctic, which holds information about his dead planet Krypton and allows him to communicate with the A.I.'s of his late ancestors.

Clark began using the Fortress much more after becoming Superman. Becoming his occasional headquarters as Superman.

Overview
The Fortress of Solitude is a vast sanctuary hidden somewhere in the Arctic. It's built entirely from Kryptonian crystals, the Sunstone. Usually is only accessible via a special key. That said, the fortress has also been accessed in other ways, such as by teleport.

Inside, the compound houses a display of items Superman collected over the years from his adventures, as well as statues of his parents. Also present is an interactive computer database, and many more things.

The facility was maintained by Kelex, who recognized Kal-El as their owner. As well as certain friends as friendly, but maintained defensive programming against strangers.

History
At some point in his younger years, Kal-El was examining his pod, within the control panel was a crystal. After touching it, the crystal triggered a hologram of his father telling him what the crystal could do. The crystal would be used to create a Kryptonian-esque home at any location of his choosing, all he had to do was place it into the ground at the location. He chose the arctic.

After his first encounter with Metallo, Clark was injured and affected by kryptonite. He visited the Fortress to speak with his father during the Man of Tomorrow event. Jor-El gave him the guidance and words he needed to become the man he is today.

Known holographic entities

 * Jor-El
 * Lara Van-El
 * Kal-El's ancestors

Chambers

 * Armory: One of the most highly guarded rooms in the Fortress, this is where Superman stockpiles various hi-tech weapons that he confiscates during his many adventures. Although he never resorts to using weaponry himself, he often studies their technology in the hopes of finding something of societal value.
 * Atomic Cauldron: Located deep in the Earth, the atomic cauldron is the most powerful furnace in the world. The cauldron operates off of liquefied Sunstone crystals and is used to provide power to the entire fortress. The cauldron is maintained by several Superman robots.
 * Interplanetary Habitat: This is a highly controlled environment filled with exotic and often endangered creatures from around the galaxy.
 * Museum/Trophy Room: Superman maintains a gallery of artifacts and souvenirs that he has acquired over the span of his career. Inside are several scale models and dioramas of Krypton and its cities. The trophy room also contains a gallery of statues commemorating other heroes he has worked with, including the Legion of Super-Heroes.
 * Science Laboratory: Superman's laboratory is one of the most highly advanced science labs in the world. Here he studies multiple substances and more.
 * Regeneration Chamber: This was an oval-shaped crystal structure that stored solar radiation.
 * Kitchen: An area with a kitchen-based appearance and items. Superman uses this room to store food and nutrients for friends, family, and pets. This area also has a dining room.

Items

 * Key: A key used to unlock the Fortress, made from condensed Dwarf star material. Due to its immense size and weight, only someone as strong as Superman could hope to lift it and unlock the massive doors guarding the Fortress.
 * Kryptonian Warsuit: A relic of Kryptonian culture, this over-sized battle-suit was worn by his ancestors during Krypton's last war. It can also be served as a mobile hospice, slowly healing one.
 * Phantom Zone Portal: A portal in name only, this is actually a large circular window into the Phantom Zone. By operating a controller, Superman can analyze various depths and regions of the Zone.
 * Phantom Zone Projector: Developed by his later father Jor-El, this device is used to transport living matter directly into the Phantom Zone. It was first used to sentence the mad Kryptonian scientist, Jax-Ur, into exile after his experiments with interstellar travel caused the destruction of a Kryptonian lunar colony.
 * Statue of Jor-El and Lara: High above the center of the Fortress rests a floating statue commemorating Superman's parents, Jor-El, and Lara. The statue is mounted on a Sunstone base and displays his parents holding up a miniature model of Krypton.
 * Superman Robots: Throughout his career, Superman has often used a variety of robots molded-in Superman's image to perform various tasks. One of the robots is named Ned and was programmed to feed and take care of Krypto when Superman is absent. Currently, a small supply of robots is used to maintain the Atomic Cauldron.
 * Sunstone Simulator: The Sunstone simulator is a highly advanced computer network that operates off the self-replicating pneumatic Sunstone Crystals. This simulator is the virtual embodiment of all Kryptonian knowledge and culture. By sliding specific crystals into their corresponding receptacles, Superman can activate a holographic simulation of his father, Jor-El. The Jor-El simulation is programmed to speak and react as if he were still a living, conscious being. Because the knowledge from the Sunstone Crystals was intended exclusively for Superman, the Jor-El hologram addresses everyone who activates the simulator as "Kal-El".