The Citadel

Location: Milky Way / Serpent Nebula / Widow

Supposedly constructed by the long-extinct Protheans, this colossal deep-space station serves as the capital of the Citadel Council. Gravity is simulated through rotation, and is a comfortable 1.02 standard G’s on the Wards and a light 0.3 standard G’s on the Presidium Ring.

Total Length (Open): 44.7km
Diameter (Open): 12.8km
Population: 13.2 million (not including keepers)
Gross Weight: 7.11 billion metric tons

The asari were the first race to discover the Citadel, soon after learning to use the mass relays. They were joined shortly by the salarians, and soon after, the volus. As other races were contacted by the asari, or discovered the station independently, they gained embassies on the Citadel and came under the jurisdiction of the growing Council, eventually comprised of the asari, the salarians, and the turians.
Strategically located at the junction of a number of mass relays leading to various parts of the galaxy, the Citadel quickly became a hub of activity. The station was chosen to house the Citadel Council, thereby cementing its importance in the galactic community. It is accepted to be the political and cultural heart of Citadel space, the unofficial name given to all systems that fall under the Citadel species’ control.

Even after thousands of years of occupation, the Citadel retains many secrets. The precise age of the station is not known, nor what resilient material it is constructed from. The location of the Citadel’s core and its master control unit, regulating systems such as life support and navigation, remain hidden. The most visible, and perhaps intriguing, mystery of the Citadel concerns its caretakers, the keepers. These mute alien creatures maintain the Citadel’s vital systems, and can be seen working throughout the station, yet, despite this, little is known about them.

The Citadel

Mass Effect: Omega Chronicles Gandriel