Fortress Of Solitude
The Fortress of Solitude is a relic of the planet Krypton hidden in a tesseract sphere in the Andes mountains. It was created by Eradicator when Superman brought it Earth as his base. It was supposed to turn Earth into the new Krypton. Stopping this from happening, the Fortress would stay hidden as Superman's secret base hidden in the arctic as a way to find out information about his past and purpose of Krypton and why he was placed on Earth.
The Early Fortress
The first Fortress of Solitude appeared in Superman #17. The fortress was built into a remote mountainside. The fortress contained various items such as trophies and objects that Superman's enemies used on him. These items include: The Archer's bow and arrows, Lex Luthor's ray gun, Count Bergac's monocle and Righab Bey's turban to name a few. Superman also used the fortress as a personal gym.
During the Silver Age, Superman has a fortress built on a cliff side with a giant keyhole. Superman uses a giant key buried in the snow to open the fortress door. When the key is buried, its top can be seen and is disguised as an Airplane path-indicator. The key is so heavy that only Superman can lift it.
This room contains souvenirs of missions performed all over the universe.
There are several rooms in the Fortress dedicated to friends of Superman like a wax museum. The Superman Room contains statures of Superman and Clark Kent.
Batman & Robin Room
A room dedicated to the exploits of Superman's friends, Batman & Robin.
On one wall of the Fortress, there is a mural that was painted by Superman, depicting how he once created an entire solar system all by himself.
A room dedicated to Supergirl.
A room containing the atomic-powered robots that aid Superman in training and in emergencies.
Jor-el and Lara Arch
Statues of Jor-El and Lara, (Superman's parents), supporting a Krypton globe, form an archway.
Ma and Pa Kent Room
A room dedicated to the memory of Superman's foster parents, Jonathan and Martha Kent.
Daily Planet Room
A replica of Clark Kent's office at the Daily Planet.
Lois Lane Room
A room dedicated to Superman's girlfriend Lois Lane.
Lana Lang Room
A room dedicated to Clark Kent's Smallville sweetheart Lana Lang.
Lori Lemaris Room
A room dedicated to Clark Kent's college sweetheart the Atlantean Lori Lemaris.
Lyla Lerrol Room
A room dedicated to Superman's love the Kryptonian actress Lyla Lerrol.
A room filled with various space creatures and specimens that Superman collected from around the universe.
Superman once used the Supermobile when an asteroid with the properties of a red sun passed over earth. The Android got free and battled the JLA and only Superman was left. Superman escaped to the Fortress and used the Supermobile to defeat the Android. It also houses a steel diary, it's pen is actually thought guided and writes whatever Superman thinks.
Other Artifacts found at the Fortress
Phantom Zone Projector: In those day, when you beam someone with the Phantom Zone projector he turns into a Phantom, no one can see, hear or feel him but they can see and hear you. Superman communicates with them using a form of telepathy. Most of the Zoner's reside on Earth since Jor El (Superman's father) was the one who imprisoned him. Thy only way to see a Phantom Zone prisoner is by a special pill. The prisoner is given a pill before he is sent to a ghost like state and when light is passed on to him his skeleton becomes visible. So far only one prisoner who swallowed the pill escaped from the authorities. This prompted the Prisoners to make an oath to help a fellow Prisoner and (even Superman) if the need be.
Bottled city of Kandor: Just like the T-Rex, Giant Penny and Giant Joker Playing Card in the Batcave, the 'Bottle City of Kandor' is a staple of the Superman lore. Originally it was the city of Kandor on Krypton before it was shrunk by the villain Brainiac.
Superman's Underwater Fortress of Solitude
In Action Comics #244, Superman had an underwater Fortress of Solitude located at grid coordinates 28 degrees North Latitude and 50 degrees West Latitude, which is in the Sargasso Sea section of the Atlantic Ocean. Superman used the underwater fortress while trapping two alien invaders. The underwater fortress made a cameo appearance in Superman #176. Superman abandoned the underwater fortress due to its location was discovered by divers. The Atlanteans use the underwater fortress as a "showplace and tourist attraction".
Doc Savage's Fortress of Solitude
In 1933 author Lester Dent created Doc Savage in his first Doc Savage novel The Man of Bronze, along with Doc he created the Fortress of Solitude-Doc's arctic retreat. Doc's Fortress was quite different from Superman's with his containing a gym, a laboratory, a hangar, a solar observatory, a hospital, a factory, and many other rooms and buildings.
Doc Savage was a big inspiration for the creation of Superman, with his first name being Clark and he had a Fortress of Solitude which Superman would later have. His original adventures also served as an inspiration for Superman and Batman.
The New 52
Following the aftermath of Flashpoint, Brainiac's origins were reset. Brainiac now is known as "the Collector" an artificial intelligences that originally developed on Culon where it believed that the only way to preserve the universe was to save the best of civilizations by micronizing them and then leaving. The Collector would infect various worlds that had a high level of AI systems with its presence before taking the main cities of those worlds. It attacked Krypton years ago and claimed Kandor before later realizing years later that a lone survivor of Krypton had escaped to Earth. Seeking out the Last Son of Krypton, the Collector made contact with Lex Luthor in order to draw Superman out. He then infected John Corben with his influence and transformed him into a cyborg under his control before taking Metropolis like he had taken Kandor years earlier.
Superman eventually stormed Brainiac's ship and made a deal that if he defeated the Collector Metropolis would go free. The Collector sent Corben after Superman, but due to Superman reasoning with Corben over his feelings for Lois Lane, he broke free of the Collector's control and joined Superman in his attack. Superman then used his rocket from Krypton that had also been micronized with Metropolis to attack the Collector's mind, which the rocket was able to due since it's primary program was to project Kal-El. In doing so, Metropolis was returned to Earth and Superman took possession of the Collector's ship and made it his new Fortress of Solitude.
At some point after, Superman abandons his "Space Fortress" and gains a new Arctic one, un-like the older versions, this new Fortress has the appearance of a giant spiky crystal ball. How Superman obtained this Fortress and whats become of the Space one is still unknown due to the 5 year time gap.
'Superfriends' TV show
The Fortress of Solitude is included in the super-friends television series. The Fortress of Solitude was essentially the same as the comic version. In one episode of the Super Friends which Superman died, the Super Friends visited the Fortress of Solitude and it required a giant key to enter the fortress, just like the comic version.
The Fortress of Solitude has appeared in various Superman films since the 1970s. This version is considerably different than in the comics. In these films, it is usually depicted as a crystal cave that was created by throwing a Kryptonian crystalline object onto the permafrost in the vicinity of the North Pole.
Man of Steel movie
In the new Superman Movie: Man of Steel. The fortress is a crashed Krypton colonization ship equipped with a birthing matrix to create new Kryptonians, It is unlike its previous incarnations made of a Kryptonian metal like substance rather then sunstone crystal.
It was destroyed during a fight between General Zod & Kal-El it remains unknown how much if any of the ship survived it's destruction!