Dark Icarr

Dark Icarr, the Shattered City, was once one of many of the City of Stars that wanders the Astral void between the myriad planes of the Uberdimension. Now the great city is a wreck. A thriving and prosperous metropolis, sure, but a broken wreck all the same.
Under the somewhat questionable guidance of Starwatcher Sybs the Myopic, the City of Stars approached a small, black star, because it "seemed interesting". Unfortunately, the city approached too closely and broke up unto a hundred large pieces and many hundreds of thousands of tiny ones. Many of these fragments were swallowed up by the dark star, and only a frantic effort by the surviving wizards saved the rest from the same fate.
Saved from impending doom, the wizards began to coordinate the efforts to connect the many fragments of the city together, a task aided by the discovery of a natural maze of inter-dimensional tunnels radiating out from the star that not only connected to each of the city fragments, but also connected to all the currently known planes of the Uberdimension, and to many hypothetical ones too. The Shattered City quickly became a hub of travel and trade, of politics and clashing egos, and of commerce, and continues to prosper to this day.
The black star was named Dark Icarr, and over time the name became synonymous with the fragments of the Shattered City that still circle it. The name apparently came to Oric the Chronogazer during a time-trance, based on the mythology of a culture that is still yet to emerge.