Elysium

Founded in 2160, Elysium is humanity's oldest colony in the Skyllian Verge, only a few hours travel from Sidon. It has a population of several million and is located at a nexus of several primary and secondary mass relays, making it a major hub for travel and commerce. Due to the fact half of Elysium's population is non-human, requiring extra screening procedures, security there is very tight.

Elysium debuted in Mass Effect: Revelation. The Alliance hero Jon Grissom retired there, and the planet provided a hiding place for Kahlee Sanders when Skarr was in pursuit. Elysium is featured in the War Hero backstory for Commander Shepard and mentioned briefly in the UNC: Espionage Probe assignment.

In 2176, Elysium was attacked by a large force of mercenaries and pirates under the command of Elanos Haliat during a battle known as the Skyllian Blitz. The Alliance repulsed that attack, leading to significant increases in patrols throughout the Terminus Systems. One of the ships at Elysium was the frigate SSV Agincourt: Navigator Pressly served aboard her and earned his commission after the Blitz.

The Jon Grissom Academy orbits Elysium.

Trivia
The planet is probably named after the Elysian Fields from Greek mythology, the final resting place for the souls of the heroic and virtuous.