Superman's Fortress_of_Solitude is many things. https://dc.fandom.com/wiki/Fortress_of_Solitude
http://dccomicsartists.com/superwhoswho/fortress.htm
https://comicvine.gamespot.com/fortress-of-solitude/4020-41185
"The Fortress contained an alien zoo, a giant steel diary in which Superman wrote his memoirs (using either his invulnerable finger, twin hand touch pads that record thoughts instantly, or heat vision to engrave entries into its pages), a chess-playing robot, specialized exercise equipment, a laboratory where Superman worked on various projects such as developing defenses to kryptonite, a (room-sized) computer, communications equipment, and rooms dedicated to all of his friends, including one for Clark Kent to fool visitors. As the stories continued, it was revealed that the Fortress was where Superman's robot duplicates were stored. It also contained the Phantom Zone projector, various pieces of alien technology he had acquired on visits to other worlds, and, much like the Batcave, trophies of his past adventures.[1] Indeed, the Batcave and Batman himself made an appearance in the first Fortress story." https://en.wikipedia.org/wiki/Fortress_of_Solitude#Original_version
https://en.wikipedia.org/wiki/Fortress_of_Solitude#Film
https://superman.fandom.com/wiki/Fortress_of_Solitude
https://screenrant.com/best-superman-fortress-of-solitude-facts-trivia
M. Brando and the fortress of solitude https://www.youtube.com/watch?v=7ujuOikKgAE
https://screenrant.com/superman-fortress-solitude-batcave-cooler-batman-lair
https://thedigitallabyrinth.blogspot.com/search?q=The+Batcave
