Zion (The Matrix)

Zion is a fictional place in The Matrix films. It is the last human city on the planet Earth after a cataclysmic nuclear war between humankind and sentient Machines, which resulted in artificial lifeforms dominating the world.

History
Following the United Nations attack upon the newly-established Machine Civilization of Zero One, a global nuclear war between both factions began for control of the Earth. The human leaders quickly realized (after several desperate plans to halt their never-ending waves of techno-soldiers) that the Machines had a higher chance of winning and began construction of an entirely underground city built for the purpose of preserving the human race. When the war ended in the Machines favour, humans were left struggling to survive on the cold, dangerous and desolate surface, which was quickly becoming uninhabitable due to the Operation: Dark Storm cloud. The Machines captured most of the survivors and imprisoned them in their newly-constructed bioelectric towers and their minds placed in the Matrix to keep them docile, but 23 survivors were freed by a mysterious Matrix-controlling figure referred to as "The One" and led to the un-finished Zion, where after making the city (partially) operational and regaining technological usage from geothermal energy from the Earth's core, the One taught the humans to continue building and maintaining a war effort, and to fight inside and outside the Matrix. After the One's death, the humans learned to survive on their own and began waging a partial-guerrilla war from Zion against the Machines, and at the same time try to free the Matrix's population from their virtual "prison".

Geography
Zion was built 4 kilometers below the Earth's surface, just above the Earth's mantle and exists entirely underground. The city itself is cylindrical (vertically inclined with respect to Earth's surface) in design and possesses many levels including;
 * Council Chambers: This level is near the bottom area of the middle section of the city. This level has a series of chambers that are used as living areas and offices for the members of the Zion Council.
 * Gathering Spaces: A level just below the Dock. This level contains many areas where homeless or new arrivals rescued from the Matrix gather to live until permanent quarters are assigned.
 * Geo-Thermal Generation: This level is near the bottom of the city. This level is dedicated to providing power to the city in the form of geothermal energy from the core of the Earth itself.
 * Intermediate Areas: Other areas of the city that have yet to be mentioned and only seen.
 * Life-Support Level: The bottom level of the city. This level is dedicated to providing life-support, in the form of water, warmth, air etc., to the city's population. In an ironic twist, the machines that do these tasks are entirely automated, but their human overseers have taken steps to ensure they can never reach sentience, and the machines have built in kill-switches that would shut them down at the first signs of sentience.
 * Living Quarters: The entire central middle section of the city. This level is dedicated to provide shelter for all of Zion's population, numbering approximately 250,000.
 * Meeting Hall: A chamber near the bottom of the city. This is where the Council convenes and meets with Zion's hovercraft Captains and Military Leaders and plans high-priority missions.
 * The Dock: The top level of the city and entrance into the underground tunnel network. The dock is operated and its systems administered by the operators in <b>The Crane Tower<b>, and provides as a recharging station and repair area for the hovercraft fleet.
 * <b>The Temple<b>: A large cavern below the city itself. This cavern is dedicated to holding religious gatherings for the entire population, and also serves as a last defensive position in the event of a complete invasion by the Machines.
 * <b>War Room<b>: A specially-reinforced chamber on the bottom level of the city. This room is used by Zion's military leaders to plan their war effort against the Machines and defend Zion in the event of an incursion.

Defences
Zion has a multitude of defensive systems that, collected together, is commonly known as the <b>Zion Defence Grid<b>. The systems consist of:
 * <b>6 Double-Barrel Turret Machine Guns<b>: The main defensive system, installed in The Dock, which serves to protect incoming hovercraft from Machine incursions.
 * <b>APU Corps<b>: 150 mechanized bipedal combat suits that are used for heavy support in the event of an attack on The Dock by the Machines. The corps is led by Captain Mifune.
 * <b>Infantry<b>: 10,000 human soldiers equipped with electromagnetic "lightning" guns and hand-made rockets & launchers, and are trained to defend the city in the event of a Machine incursion.
 * <b>Hovercraft Fleet<b>: 30 electromagnetically-powered hovercraft who continuously fight the Machines in the real world with EMP weapons, and its crew fighting to free the Matrix's captive human population by journeying into the Matrix itself.

EMP devices, despite being installed on every hovercraft in the fleet, were never installed in Zion's defensive grid (even as a last resort), primarily because the city possesses no EMP shielding what-so-ever. Though an EMP could be used and every Machine in its range instantly disabled, the defensive grid, APU fighters and virtually every piece of defensive hardware in Zion would be permanently disabled as well, leaving the city with no way to defend themselves during a second Machine incursion.

It was later revealed that none of Zion's defensive systems were sufficient enough to withstand the juggernaut of the Machine's army, and the city's total destruction and death of its entire population was well within the Machine's power, but never carried out due to its purpose (see below), but an attack could be ordered on the city at any moment by the Architect.

Leadership
The city is governed by the Zion Council, which makes all administrative decisions for the city and the war effort. Other officials were recruited to report directly to the Council and carry out their orders on their behalf, including (reluctantly) the supreme commander of the Zion Defensive Forces; Commander Jason Lock. The captains of the Zion Hovership Fleet also have strict access to key data in the Zion Mainframe, and also have political bearing with the population.

Purpose
Zion was initially built for the purpose of saving the last of the human race following the war against the armies of Zero One. However, a Machine program named <b>The Architect<b>, the creator and manipulator of the Matrix, manipulated the situation so Zion served as a control for the survival of the program in two ways. Firstly, the Machines could allow any humans who did not, or could not, accept the Matrix for what it was to live in the physical world without having to recapture them (the effect this produced reduced dissent within the Matrix's population and prevented an exponentially-growing rejection rate from its population from causing entire "crops" of humans to die out, reducing power output). And secondly, the Architect would periodically destroy Zion and its inhabitants as part of a deal coercing The One into reinserting the "Prime Program", a program code required to maintain the Matrix and needed to be inserted every 100 years, allowing the Matrix to continue and Zion to be rebuilt by chosen survivors without memory of the destruction (the alternative was a catastrophic system failure that would cause the entire system, including the Matrix, to crash and kill the overwhelming majority of the human population and, coupled with Zion's destruction without any people chosen to survive, would cause the extinction of the entire human race, though the Machines would "go to any level to ensure their survival"). This cycle was broken when the sixth installment of The One refused to re-enter the program, and instead brokered The Truce with the Machines.