The D’ni first sent a group to build a monument at their chosen mark for the Great Zero on Ae'gura in the year 0.

Though in 1817 Me’Erta suggested that the line of the Great Zero was inaccurate eventually in 3112, Rakeri announced that the old line of the Great Zero was accurate and should be honored again.

The Great Zero was a central landmark for the D’ni and construction was constantly centered around it. Over many years and numerous construction projects, the original monument built in the year 0 was fortified and added to, leading to a fairly large structure at the fall of D’ni.

The Great Zero itself was usually based on a prominent natural landmark within an Age. From the Great Zero a line was drawn, usually toward magnetic North, to aid in navigation, construction, etc…(Note that the D’ni measurement and spatial system was based on a polar coordinates, rather than rectangular.)

As had always been the case with the Ronay, a group of surveyors was sent to D’ni, before the group officially moved there, to establish the Great Zero and the line emanating from it. A monument was built on the Great Zero in the year 0 DE.

Unlike, previous occasions, Ri’neref established the line of the Great Zero as set apart for holy buildings. Without authorization by the reigning King, construction was forbidden.

Though it’s never stated directly, records strongly imply that it was Ri’neref who chose where the city would be established. He seemed to base his decision on two factors (which probably made the decision an easy one). First was the line of the Great Zero. It seemed an obvious spot to base the city, with the most important religious structures being directly on the line and the rest of the city surrounding its center. The second factor was a group of waterfalls that flowed from the ceiling of the cavern to an area adjacent to the line of the Great Zero. The fresh flowing water was perfect for drinking.