DISCLAIMER!!!
This is by no means a replacment for the current UPS Earth. Rather it is a seperate world that was very similer but ended up being as it is now. Think of this as the Athas of UPS if you will.
The city of Hub.
Built from the ruins of a destroyed reswearch facility and around a massive stable portal this city is one of the largest on Planar Earth. Hub is a city of trade and of intrigue for the planes themselves were pulled partly through that fateful day when mankind attempted to create a 'rift' with their newly refound magic. Instead of creation they wreaked chaos. The portal they created utter devastation acting as a catalyst and causing more and more portals to spring forth. This world was simaler to our own mundane world save the prescence of magic at the same level as the urban arcana setting. The world after Seven Days was utterly changed Ley-lines glowed with a strange prescence and the planes have spilled over. Hub was one of the first cities to come about after this chaos. Created by humans and outsiders under an uneasy truce this city is the shining star of this post-apocalyptic world. Each 'Ward' is a collection of neaighborhoods built around a specfic small stable portal to it's home plane.
The Elemental Wards:
Air Ward: One of the first wards to be established the air ward is imbued with the nature of the elemental plane of air. It's buildings stretch to great heights and a gentle breeze is always movving through it. On occaision this ward will be swallowed up in cluods of fog or steam due to it's close proximity to both the fire and water wards. The Denziens of this ward range from air elementals all the way to those who wistfully dream of flying through endless skies. This ward holds little say in the manegment of Hub and typically keeps it's opinoins to itself.
Earth Ward: Located next to the fire and water wards and opposite to the Air ward this seemingly empty collection of squat buildings can be very misleading. In truth, these are simplay entrances to the actual Ward which is a series of tunnels and carverns that run beneath Hub. This has made the Ward a prime method of travel during the winter months or during storms and also an excellent place to be lost in. The numerous tunnels are winding mazelike and only those trained or well equiped truly know their way through this maze. The inhabitants of this ward are primarily dwarves, dao and earth elementals.
Water Ward: Loacted between the Air and Earth wards and across from the fire ward this is the smallest of the elemental wards and at the same time most important. The majority of Hub's fresh water supply comes from this ward as does a regular and steady supply of fish caught from the several underwater areas. These sunken sections of the city hold actual portals to the plane and allow creatures to easily move onto earth through the rifts. However travel to the other side is diffucult if not deadly for many. The water ward is not completly submerged however and much of it still remains at surface level, it is not uncommon for a person living there to have a section of their home submerged for the occaisional 'special guest'. The most common inhabitants of this ward are creatures that are at home in the water or are amphibious. However, several small groups of humans have established fishing operations here as well.
Fire ward: The largest elemental ward this soot choked area is an industrious and high energy ward that serves a vital purpose to Hub. Comprised of only stone and metal building and streets caked in ash this ward is always hot and has never seen snow. Loacted around the ward are open pits leading into firey infernos. These 'incinerator gates' as they are called are the primary method of trash removal in Hub. One can simpley toss away whatever they need to have quickly removed. The Fire ward is home a wide variety of creatures including elementals and salmanders. Several Efreeti call this ward home as well.
The Slums-
The combined wards of Limbo, Hades, Acheron, and Pandemonium this mazelike section of Hub is ripe with danger. Gangs of ruffians fueled by the mindless violence of Acheron roam the streets attacking other 'rivals' for no real reason or purpose. Brandishing weapons that most armies would now envy. Limbo has twisted the slums into a constantly shifting maze. Entire neighborhoods 'drift' about dissapearing and reappearing at random. Many have made a lucrative profit by reporting where abouts particular neighborhoods are currently are. Slaadi appear and dissapear with them preying upon the unsuspecting. Hades has become a mystery, there is no doubt that there is a large amount of homeless in the slums, many blame the curse of hades saying that it entraps them and causes their misery. Many dismiss this as rumor and superstition but there is something to be said about the wards entrapping nature. Pandemonium has played a more subtle role as well, the narrow, warren-like structure is no accident during windstorms the air is funneled and focused into a maddening, shrill, scream that eats away at the nerves. To prevent widespread insanity many buildings have areas that soundproofed. This has led to a lucrative 'backroom' dealings method amongst many of the criminal elements of the slums.
The Outers Wards- The outerwards are the truly stable sections of Hub. Unlike the Inner Wards which are filled with the constant movement and industry needed to supply Hub The Outer Wards take their natures from the various outer planes and look as such. During the early days of Hub this region of the city was a veritable warzone as Celestials, Devils and Demons waged a constant struggle for power over their newly found world. Thankfully much of this fighting came to an end when high ranking members of the various exemplars came to realize that with the massize amount of wild magic made it impossible to return. Peace treaties were drawn up as fate settled in. The lawful outsiders in specific the celestials, harmonium, Devils and the Human survivors. The first order of buisness was the rapid expulsion of the Demons that roamed the streets and posed a threat to the general populace. To this extent they built the Prison tapping into the carcerai rift to supress the abyssal rift and bansish those within Hub. Unexpectedly this had an adverse affect on the rest of the planet portals to abyss ripped open along the major leylines. Fiends spwed forth and dealt the killing blow to much of the surving human populace.