}} (Observation room)
The Great Zero is located at the pinnacle of Ae'gura, the D'ni capital. Set up in the year 0 DE by the initial surveyors of D'ni, the Great Zero was the linchpin of the D'ni navigational system. A monument was established at the site of the Great Zero, which was added to throughout the time of the D'ni empire.
King Ri'neref made an unusual distinction with the Great Zero in D'ni: he decreed that the line coming from the Zero be dedicated to religious structures. No construction could be made on the line without the approval of the reigning king (and presumably the Great Lords once the kingship was abolished).
In 1817 DE, King Me'erta suggested that the line from the Zero was incorrect, and all temples built during his reign fell along his proposed—but never officially decreed—line. However, in 3112 DE, King Rakeri declared that the original line was indeed correct and should be honored.
Layout and access
The Great Zero complex can be broken up into three segments: the observation room, the courtyard, and the calibration chamber. Access to each of these locations is dependent upon a visitor's KI calibration state. Visitors begin in the observation room, and additional access is gained by completing marker missions.
The observation room is a small structure at the front of the complex. It is elevated above the courtyard area, with no means in ingress or egress except through linking books. Visitors can use the marker mission dispenser to retrieve and upload the first "green" mission. Completion of this mission unlocks the user's KI to access the courtyard linking book in the Nexus.
The courtyard is a large, round area with a massive piece of machinery at its center. This rotating machine emits a powerful neutrino beam, and is the origin point for the Great Zero coordinate system (commonly referred to as the "KI Positioning System, or "KIPS"). Large crystals ring the courtyard's high walls, and static electricity can regularly be seen arcing between them and the crystal at the machine's center. A flow of purified water runs down into a basin below the machinery from the calibration chamber.
This cathedral-like building at the far end of the complex houses a set of four calibration marker mission dispensers, which visitors can access to retrieve and upload the marker sets used to calibrate the Great Zero's KIPS hardware. Beyond the open windows, a natural waterfall cascades through a large, orange bank of purifiers before flowing into a large pool. A beam of energy runs from this purifier bank into the chamber, and out through the wall facing the rest of the complex.