Nudrun Orreries

From Halo: Daybreak

Without a doubt, the celestial orreries at Nudrun are one of the most spectacular of the Forerunners' known creations, appropriately considered one of the Twelve Divine Wonders by the Covenant. An entire star system carefully engineered, with planets and scores of moons in geometrically perfect orbits nestled within systems of artificial rings much like in a mechanical orrery. While not unique nor entirely intact, nor particularly useful as a technology cache, it is the best preserved collection of such megastructures and one of the most powerful reminders of the Ancients' might.