Location from Mass Effect by BioWare
An asari commerce world at the edge of Citadel space — beautiful, wealthy, and operating under the legal minimalism required to compete with the Terminus Systems.
Illium is an asari colony that has made itself indispensable by positioning between Citadel law and Terminus freedom. Drugs are legal if labeled. Weapons of any kind can be purchased. Indentured servants are bought and sold under contracts that technically comply with galactic law. The corporate legal framework is designed to stay just inside what the Citadel will tolerate while offering what the Terminus can't guarantee: security. Liara operates here in ME2 as the Shadow Broker's base. The asari matriarchs who ostensibly govern Illium have decided not to notice this.
A garden world with an atmosphere slightly heavier than Earth standard, seen from approach as blue-green and clearly inhabited at scale. The city of Nos Astra is all vertical glass and repulsor platforms, the exchange trading floor visible from the landing pads, the whole place humming with the specific energy of money moving fast. Very few quarians visible — the Migrant Fleet is not welcome here.
Also known as: Illium, Nos Astra