The Last City

In Destiny, The City is the last city on Earth and the last bastion for mankind and civilization.

Background
It is unknown where The City is located in terms of modern-day regions or continents, but based on several pieces of pre-announcement concept art, some speculate that it is located in Puerto Princesa, Philippines.

The City was built after The Traveler arrived, and is located directly below where The Traveler hovers. According to the Reveal Trailer, mankind came together to build The City underneath the Traveler because it provides powers and protection to man.

In-Game
The City appears to function as the hub for player activity. Speculation is that it operates as a home base or "safe zone" where players can meet up to go on missions, take a breather and recharge from fighting enemies, and/or exchange and trade items, weapons, and armor.

There have been no confirmations as to The City's function or scope in Destiny as of yet.

Zones
The City appears to be designed to have several zones. It is unclear how many zones there will be or what their function will be. Thus far, only one zone, the Overwatch District, has been confirmed.