Silver City

"So as it turns out, the Covenant are here to stay. The Arbiter is leaving a naval force behind to defend Earth, and that force needs a starport to call home. Fair enough. They want to build a port on Luna. That's fine. There's a lot of real estate that just opened up there. But rumor has it that they specifically requested a patch of land on the western hemisphere, the leading edge of the moon. The Separatists don't just plan to garrison Earth. They're going to march around it on patrol."

- Staff Sergeant Joseph Barnes

The Silver City is a major civilian center and military base established by the Concord of Reconciliation in the Oceanus Procellarum, Luna.

History
The Silver City's origins laid in the Treaty of Arusha, signed by the Schismatics at the time. It stipulated, among other things, that they would be granted a permanent base of operations in the Sol system, which would allow their ships and armies to resupply themselves in the Human Sphere and would guarantee a fleet to defend the system. What form this took was subjected to significant debate: Arbiter Thel 'Vadam desired it to found it in East Africa, close to the Kenyan Excession so his forces could watch over the artifact. The civilian leaders of the regional nations and the United Earth Government vehemently opposed this, due to concerns with the population's response to such a large ex-Covenant presence on Earth and lingering distrust over the Sangheili themselves. In response, the UNSC Navy proposed that the Covenant build a remote space station or use one of the lesser-populated moons of Neptune.

Ultimately, both sides compromised. The Arbiter's coalition was given land the size of New York City on the leading face of Luna. Given a lease of 99-years (which could be revoked if the treaty was violated), what would become the Silver City was designated as part of the Schismatic's territory, governed by Sangheili secular and religious laws rather than those of humanity. When the first foundations were laid, the plan was to build a naval command base and embassy for future diplomatic discussions.

At some point, the Silver City's unique legislative characteristics led to severe tension. An ODST was caught drawing graffiti in the Silver City that equates "The Light of High Charity" to the glassing of human colonies, infringing on their blasphemy laws. He was arrested, and though he was briefly broken free by his colleagues, he was quickly recaptured and put on trial. However, Thel 'Vadam himself arrived to testify for him, citing an old law prevented those born outside of the Covenant's borders being sentenced for religious crimes. This led to the case being dismissed, and served as a precedent for all future cases that involve humans.