The Citadel was a Crucible map located in the Dreaming City in the Reef. It was vaulted with the release of Beyond Light. Destiny 2 Game Director Joe Blackburn has confirmed that the map will return to the game during the final Season of Lightfall, Season of the Wish. According to Jeff Horal, Senior
Peekis, Destiny Wiki
Darkness - Destinypedia, the Destiny wiki
The Citadel - Destiny 2 Wiki - D2 Wiki, Database and Guide
Forsaken - Destinypedia, the Destiny wiki
The Citadel - Destinypedia, the Destiny wiki
The Citadel, Destiny Wiki
Twilight Gap (Crucible) - Destinypedia, the Destiny wiki
Destiny 2, Bungie Wiki
Distant Shore - Destinypedia, the Destiny wiki
The Fortress - Destinypedia, the Destiny wiki