In Superman and its sequels (except for Superman III, in which it did not appear), the Fortress is created by a crystal that Jor-El enclosed in Kal-El's spaceship. The crystal leads teenage Clark Kent to an ice field where it is "planted" by Clark, after which it melts into the ice and grows into a huge crystalline building, similar to the crystalline architecture shown on Krypton at the beginning of the film. This fortress was also used to start Kal-El's 12-year training to become Superman. This Fortress contains numerous "memory crystals" that can be used to access Jor-El's artificial intelligence and hologram, interactive holographic recordings of Lara, and other Kryptonians, and a chamber that uses red sun radiation to strip Kryptonians of their super powers.

In Richard Donner's cut of Superman II, the Fortress is destroyed by Superman as its existence was revealed to Lex Luthor and his henchwoman, Eve Teschmacher. However, Superman then turns back time (à la 1978's Superman), so technically the Fortress is completely undamaged, while Zod, Ursa and Non are returned to the Phantom Zone.

In Superman Returns, the Fortress follows the same formula as the earlier movies, but goes into more detail about the crystal origins of the Fortress and Kryptonian architecture. Lex Luthor attempts to use memory crystals he stole from it to create a new land mass in place of America. An observation is made (following Superman II) that he acts as though he has been there before. The crystals that power the Fortress were lost when Lex Luthor's assistant dropped them out the escaping helicopter into the ocean below. The tie-in book, Superman Returns: The Visual Guide lists the Fortress as sitting on "Fletcher's Abyssal Plane".

In February 2021, Ta-Nehisi Coates was revealed to be writing a new Superman film for the DCEU that was in early development. J. J. Abrams was set as producer alongside Hannah Minghella, with no director or actors attached to the project yet. The film was expected to feature a black actor portraying Superman, with potential for Michael B. Jordan to take on the role. Coates said he was looking forward to "meaningfully adding to the legacy of America's most iconic mythic hero", while Abrams said the film would tell a "new, powerful and moving Superman story". This was reported by outlets as being a reboot of the franchise, but Richard Newby of The Hollywood Reporter felt the film starring a black actor could indicate a new version of Superman that could exist alongside Cavill's portrayal within the DC Multiverse. Newby also noted that Coates' history as a non-fiction author and journalist focusing on African-American issues would give him "the insight and experience to delve further into the [Superman] mythos in a way never seen on screen".

The studio was in the early process of finding a director for the film at that point, and had committed to hiring a black filmmaker for the project. They had met with potential directors by early May, working from a list that included Steven Caple Jr., Ryan Coogler, J. D. Dillard, Regina King, and Shaka King. Coates was not expected to deliver his script for the film until mid-December, and was believed to be introducing a new version of Kal-El / Superman in what was potentially a 20th century period piece. The film was expected to be set in a separate universe from the DCEU at that point.