(1e/2e/3e Great Wheel) Grenpoli - the Baatorian city of Diplomacy. If hell had lawyers, and it does, this is where they would all be trained. It's a wonderland of structured, subtle tyranny, with the dehumanizing brutality of hell whitewashed and replaced with gilded splendor for the benefit of mortals and planar travelers. Commerce, trade, and erinyes tutors.
(1e/2e/3e Great Wheel) Center - the city at the tangent point of all three layers of the Gray Waste. Ruled by an enigmatic, 'loth blooded tiefling named Dandy Will, segmented out into three iron-walled sections, each of which borders its respective layer of Oinos, Niffleheim, or Pluton on the city's exterior wall. Oddly enough, the 'loths make no attempts to rule the city themselves.
(1e/2e/3e Great Wheel) Death-Of-Innocence - one of the few places free of the spiritual leaching and wasting of the Gray Waste. Situated within the frozen forests of Niffleheim, almost adjacent to the border of the domain of Arawn the Celtic God of Death, the buildings and walls are all built from the evergreens of the surrounding forests. All of the trees so used however perpetually weep fresh sap, almost as if the city were bleeding.
(1e/2e/3e Great Wheel) Shrakatlor - military capital of the githzerai of Limbo. Imagine a city formed and sustained by the collective mental exertion and wellbeing of its inhabitants, and that's what this city is. If they all blacked out, the city would slowly begin to dissolve back into the roiled chaos of Limbo. And of note, these are the githzerai followers of Zaerith Menyar ag Gith, not the monastic githzerai who actually stand outside of the mainline of their species.
(Pathfinder) Galisemni - the City of the Infernal and the Divine, adrift within the Maelstrom borderlands, tugged along by the metaphorical tide of shifting landscape that changes as its proximity to the borders of the other planes of the Outer Sphere waxes and wanes. Unlike other places of structure within the Cerulean Void, Galisemni faces no opposition from the proteans, which possibly points to some sort of bargain by the city's creators with one or more kekatar choruses, or the entire city being a construct of their creation in the first place. - of course at the momen, Galisemni is just a name on a map of the Maelstrom, let me get back to you on this one -
(Pathfinder) Awaiting-Consumption - daemon city in Abbadon. The name describes the city's function as it relates to the mortal souls dwelling there. Think of it as something between a larder, a stockyard-city, and Hansel and Grettel's cage where the witch fed them wonderful sweets to fatten them up to her liking. The fiends do this for the inhabitants, allowing some more freedom than others, quite literally to allow development and evolution of the soul to alter its eventual taste. But make no mistake, oblivion cannot come quickly enough for a majority of those trapped here, be it those in chains or those in temporary priviledge.
(Pathfinder) Axis - the city/plane of Axis stands as the epitome of manifest Law and the golden representation of a perfect city. Above ground the city's streets and buildings radiate outwards from Pharasma's Spire, ultimately ended at the golden exterior walls that rise up at the edge of Axis and the start of its edge adjacent to the Maelstrom's borderlands. The Axiomite Godmind and its children ensure the city's operation and its continued expansion out against and into the Maelstrom, spearheaded by their construct armies of inevitables. Belowground and drifting above the city in golden latticework wasp hives, the formians work alongside the city's masters. But even deeper, the god of murder and deception rules his own domain like a very real, idealized urban underworld, rotten and coexisting with the perfect city above.
