The Citadel of Ricks

The Citadel of Ricks is a location from Rick and Morty that appears in The Knights of the Multiverse episode, Capital of Jerks. It's a secret society where multiple versions of Rick Sanchezs and Morty Smiths have formed a society built by their counterparts from an infinite amount of realities surrounding the Central Finite Curve, and are controlled by the Council of Ricks and the secretive Shadow Council. For some Ricks and Mortys, it is a leisure point and meeting point, but it also serves as a permanent residence for an untold number of Ricks and Mortys that have decided to settle at the Citadel and make it their home. Though its true population is relatively unknown, some Ricks have said "Whoever is still exploring the citadel, is either stupid, or one of the unfortunate millions held hostage by their terrible ideas," suggesting that it is in the millions.

Pre-Series
Through various universes, multiple versions of a scientist named Rick Sanchez have been involved in resistance groups against the Galactic Federation, as well as other groups who consider their genius a threat, such as galactic terrorists, sub-galactic dictators and most of the entire Intergalactic government. To protect themselves and hide from opposing groups, a "few thousand" alternate versions of Rick decided to join together and create their own society. It is presumed the Citadel was in a dimension specifically created by Ricks. The Citadel is known to have existed for at least 15 years. At the time of its foundation it was likely solely inhabited by Ricks, who would have been in their 50s or younger, but more and more Ricks continue to join the Citadel to this day.

A force referred to as the "Citadel's militia" performs military and security duties for the Council of Ricks. The militia is comprises mostly of uniformed Ricks, including their commander-in-chief, but some Mortys are also in their ranks.