Location from Mass Effect by BioWare
The Alliance's main fleet base and the seat of military power for humanity in the Milky Way — where Admiral Hackett commands the Fifth Fleet.
Arcturus Station is where the Alliance Navy concentrates its command authority. Admiral Hackett operates from here. The most significant Alliance strategic decisions of the trilogy pass through this station. It is also where Commander Shepard was under house arrest in ME3 — technically Alliance jurisdiction, technically answerable to the Council investigation into the Bahak system incident. The Reaper invasion of Earth ended that investigation by giving everyone more immediate problems.
A large military station orbiting a star in the Arcturus Stream, built in the functional aesthetic of Alliance military architecture — everything visible is either a weapon or something that supports a weapon. It is the most defensible human-built installation in the galaxy, and it looks it.
Also known as: Arcturus Station, Arcturus