Zion is the last, only known human city on the planet Earth. The city is the launching point for The Resistance against the Machines that threaten their freedom.
Zion, a city of over 250,000 humans, is actually a massive series of caverns deep under the ruined planet's surface, close to the planet's core, for warmth, power, and protection. Based on the understanding of the human government living there, the location of Zion is unknown to the Machines, until the Machines found a way into it through the Dock.
Zion is composed of several levels. These include:
The fortified gates of Zion open as the Nebuchadnezzar approaches.
Zion docks
The Dock: A heavily armed and fortified area where Zion's hovercraft dock for recharging and repair. The Dock (and Zion itself) has a single entryway for her ships, which opens up to a long corridor filled with gun turrets and other weapons in the event of attack. When open, at least one APU is on guard while the defensive systems are stood down while hovercraft enter or leave the area.
The Living Levels: The largest area of the city, these series of caverns that form a complex series of levels is the city proper for most of its population.
The Mechanical Level: Generally not populated, these series of purposeful but deliberately simple series of Machines keep Zion habitable through waste reclamation, water purification, electrical power, and atmosphere services.
Zion also has a complex library, where the history of humanity (in as much as it can be gleaned from the destroyed fragments found after the first Machine War) are stored.
Zion was built by humans underground after their world's skies were scorched and invaded by the relentless Machines. Neo, of course, brought the war to an end, and it may still exist as a thriving providence as Earth recovered.
