Throughout the span of Superman's career, he has maintained three different locations as his Fortress of Solitude. Many years ago, Superman placed himself into a self-imposed exile from the planet Earth. During this journey, he met an aging alien known only as the Cleric. The Cleric recognized Superman as the Last Son of Krypton and gave him an ancient Kryptonian artifact known as the Eradicator. The Eradicator represented the sum total of all Kryptonian knowledge, lore and culture. Superman brought the device back to Earth, but when it began behaving strangely, he buried it deep down in a fissure in Antarctica. The Eradicator was still active however, and it opened up a dimensional portal and extracted various resources that it used in an effort to recreate Krypton on Earth.
This also included the creation of robotic servants, patterned after the maintenance droids that once serviced the House of El on Krypton. Despite the Eradicator's attempts to convert him and the rest of Earth into a new Krypton, Superman kept the Fortress as it was the only thing he had to his home. However, it would be destroyed when the Eradicator, under the guise of the "Last Son of Krypton", absorbed the energies of the Fortress to heal himself after nearly being killed by the Cyborg Superman. Superman would later rebuild the Fortress, only to have it destroyed by Dominus during the Man of Steel's time as "King of Earth".
A second Fortress would be built by John Henry Irons, using terrasect technology to create a mobile, compact Fortress, though this would be destroyed as well. A third Fortress would be set up before the events of the Infinite Crisis in the Amazon. However, this would be abandoned quickly and turned into a tourist attraction. The current Fortress was set up after Superman launched a Kryptonian Sunstone into the Antarctic, the Sunstone's power creating the current base.
- Arsenal: One of the most highly guarded rooms in the Fortress, this is where Superman, past and present, 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.
- Bottled City of Kandor: Kandor is a miniaturized city populated with people from various alien cultures. It is named after the original Kandor City, a lunar colony from Superman's home planet, Krypton. Superman keeps the shrunken city inside the Fortress for safe-keeping.
- Interplanetary Habitat: This is a highly controlled environment filled with exotic and often endangered creatures from around the galaxy. Some of the animals found in the habitat include, a Sun Eater, the Metal Boar, the Black Mercy, the Duplorian Hawk and the Thought-Beast.
- 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 heroes, both from the Justice League and Legion of Super Heroes, that died during the Chrell War.
- Science Laboratory: Superman's laboratory is one of the most highly advanced science labs in the world. Here he studies the substance known as Kryptonite in the hope of finding a way to reverse its effects on Kryptonian physiology. He also uses the lab in an attempt to cure Daxamite lead poisoning. Superman also uses the lab in the hopes of finding a way to restore the people of Kandor to their normal size.
- Key: This was originally a giant golden key mounted on a peak some miles away from the Fortress. 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. Superman has since removed it from its original position and relocated to the Museum inside 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 also served as a mobile hospice, slowly healing Superman of his injuries after a fatal run-in with Doomsday.
- 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 intersteller 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 Kal-El'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.
- Ree-Van recently added the giant golden statue of Kal-El from the ruins of Centennial Park in Metropolis. The statue was damaged during the Chrell Invasion, but Ree-Van was able to salvage it and repair it to its former glory.
- 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 surviving robots was named Ned and was programmed to feed and take care of Krypto when Superman was absent. Currently a small supply of robots are used to maintain the Atomic Cauldron.
- Sunstone Simulator: The Sunstone simulator is a highly advanced computer network that operates off the self-replicating mneumatic Sunstone Crystals. This simulator is the virtual embodiment of all Kryptonian knowledge and culture. By sliding specific crystals into their corresponding recepticles, Superman can activate a holographic simulation of his mentor, Kal-El. The Kal-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 Kal-El hologram addresses everyone who activates the simulator as "Ree-Van".