The city of T'Ell never sleeps. It's a rare vertical city of traders, home to many races and cultural enclaves. From the dayside dwellers in the City Above, Arcade and Terraces to the night dwellers in Cavernside and UnderDock it bustles and haggles through the hours. There are certainly older cities about in the worlds, but at over a millennium T'Ell was easily the oldest city that any local knew of. Frankly, it was amazing it existed as only a very quirky set of circumstances could explain it. Parts of T'Ell like the Arcade were built in the long lost Kellian Empire and buried by the catastrophes of the Storm Years. Mountains fell and skies burned as the new moon formed its orbit, forever scarring the world. A few parts might even predate that terrible upheaval, thought no one could say for sure. Certainly when the great caverns of the Under Roads had been formed or settled, were mysteries as well. Perhaps in the Storm Years, perhaps earlier. Cavernside had been inhabited as long as the City Above or even longer. None of the current Drow elders would say or could say. Certainly not for free if they knew. Information like that would truly cost you to hear details.
As magic crept back into the world the Gates deep down in Cavernside reactivated after untold centuries of slumber. The area about the Gates was fought over extensively, but it was quickly apparent that no single group could hold them. The combined city came about soon thereafter as a solution. As most compromises go it hasn't made everyone happy. On the other hand it makes enough wealth that most would never risk killing the golden goose. Standardizing and recording the protocols and agreements between groups let to the Commercial Code of T'Ell.
Over time a preeminent family became 'First among Equals' as chair of the council became hereditary. Currently, the Felkarl clan are the official rulers and deal brokers with the surrounding lands. As the recent Airhurst Empire arose they negotiated status as a chartered free-port and incorporation as an allied country to preserve a large portion of autonomy. The other groups hold seats on the council based on that original charter. A few seats have changed hands and it's rumored one charter copy is missing, though no one seems to know which.
Free-port it is, because just about anything is for sale in T'Ell if you shopped the right places. There are a few limits on what can be easily traded in the city. Selling sentient slaves is right out. Bonded indenture are allowed, but with limits. The indenture has to be set in the city Commercial Court and be ruled fair to both parties. Transshipment of slaves is discouraged but might happen under certain rare conditions. On the other hand, a serf or slave only has to reach the city and stay for a year plus a day, while paying taxes. If they do they become a freeman, well, a free taxpayer technically. Many would get their tax ID tattooed on them as proof of that payment. From that point forward, they counted as a taxpayer and capture or removal from T'Ell fell under 'Restraint of Trade'. As the economic engine that drove the Northlands that could become serious.
The arcane 'Commercial Code' of T'Ell was the binding law for all contracts and transactions. Run afoul of it and no Trader in T'Ell would deal with you or your agents. There were sanctions, like forbidding access to the Gates or the city itself. No sane being would ever risk finding out all of the penalties. That didn't stop some from buying or selling slaves, but not within the city limits and not a known taxpayer. Even the Drow were cautious to not violate the Code, openly. There were lots of ways to run afoul of the Code. Weapons of mass destruction could become instruments of financial ruin if handled wrong. Don't declare it and try to sneak it through? Better not get caught, because the fines levied would be ruinous. Anything that could disrupt the flow of trade was scrutinized. Not to say dangerous things didn't pass, of course they did. They simply had to be packaged and warded to the specifications of the Code and monitored while in the city. There were brokers and facilitators whose entire business was navigating the byzantine Code and providing lawspeakers to get the permits for transshipment. Expensive, but when it came to the safety of the trade through the city all the major players agreed.
Over time life in the city has changed many groups. The Drow are likely the most extreme example. Much of their competitive nature has shifted to external trade, rather than internal backstabbing. Not to say that hostile takeover isn't a fun Drow hobby. It's just that many have come to understand and negotiate 'limited partnership' deals and count money instead of body count, or at least with it. Conflict within Drow cities keeps houses strong to take on all competitors, in theory. Weakened houses die, and the survivors are stronger. The Drow soon noticed that the houses in T'Ell that suppressed internal conflict and held to trade rules prospered. The houses that wasted internal resources died.
Drow are deadly competitors and cunning contract writers. Better have that contract looked over carefully by a qualified lawspeaker if you’re making deals. The game of penalty clause is a contact sport for Drow. When the deal is right you can find Drow merchants haggling with Elven factors or about any other race. A deal is a deal. That's why many large inns and restaurants provide large booths or private rooms for long negotiation sessions. And separate doors on different streets. Privacy wards and registered notaries can also all be supplied.
Trade houses, corporations, partnerships and brokerages all combine in a soup of commerce. In general they're all called houses as most have some level of clan or family ownership.
Most of T'Ells residents are at least bilingual, speaking a natal language and the polyglot Trade at the minimum. Most will also speak Westron, the local 'common' of the Airhurst Imperium. Many understand more than they can fluently speak as listening to other conversations is a fun local hobby. Information is worth much in a city of trade.
Due to T'Ell's official stance on tolerance there are three major cathedrals and a bunch of shrines in town, to any religion but Krell the Deathgod. The cathedrals are grouped together, giving opposing views a local meaning. The last bastion of the Stormkings next to the cathedral of Solaris is the subject of many a painter. Sort of a rite of passage for the many art students studying locally. Most of the major schools and universities are across the river in the metropolis of Velchea. There are a number of smaller specialized schools in T'Ell, but you have to know where to look.
As most large cities do, T'Ell has gangs. They're organized on racial or regional lines and many overlap to some extent. Some are more dis-organized but all struggle to survive. As long as they don't cause major disruption they're ignored by the city. With merciless pruning if they do get official notice. If you know how to look there are discrete gang sign symbols in most parts of T'Ell. In fact there is a 'no gang' sign as well. Certain places in the Arcade and lower regions have become negotiated safe zones between the gangs, where routes of passage from claimed territories to the shared regions are marked. There's a notoriously good pastry shop in the Arcade that's a great example of the 'no gang' rule. Pika's is a bakery run by a Hobbit clan. You can find members of gangs that would normally be mortal enemies sitting about and trading stories there. Get them out of the zone and they may still come to blows though. Within the zone the group dynamic is to trash any one who breaks the truce. They have to, as being excluded from the meeting place limits a gang to stale news. And that was crippling. Even the gangs needed information to survive.
Culturally the best description is a genteel cosmopolitan air laid over a frantic business ethic. Given the crowding and intermixing the underground sections of T'Ell might have certain groups predominate, but no area was uniform. The Terraces were mostly Halflings and Hobbits, but there were orcs who wanted a home with access to the sky. The City Above was mostly humans and half-elves but there were others scattered in the narrow row houses. In fact, it was one of the relatively cheaper areas to live as the heart of trade was in the Arcade and below.
Not that living below was a hardship. At sometime in the past artificers of great skill had been imported to ventilate and light the Undercity. Shafts held mirrors and cunningly crafted crystals to capture and reflect light below. Just up the river was a gasworks where gas was manufactured for cooking and lighting use. Service was available in large parts of the city for a fairly low cost. Intakes upriver brought in water that poured through miles of pipes and underground canals. Water powered lifts and spun waterwheels, powered trip hammers and ground grain. In fact, a lot of grain. One of the major products of T'Ell are forms of waybread that have elements of Drow and Elven styles. There were many recipes, each hoarded by a different house and aimed at different markets. Quality varies and tastes run from 'tastes like Dwarf bread' to 'I'd serve this as a dinner loaf' goodness, as does price.
Baking certainly makes many neighborhoods and caverns quite aromatic. Most of the baking companies run shifts around the clock, never letting the ovens cool. A few times a year they do, cooling them enough to let workers in heat resistant suits in to repair and service the tracks and mechanisms for the baking carts that run through the large ovens. Food is always profitable, somewhere. T'Ell ships a lot of waybread as it's always in demand.
Many who visit T'Ell are surprised by the lack of trash and smells. Waste products are gathered and hauled away to become fertilizer or fed to something. An entire culture of rat-folk lives by hauling off refuse, cleaning sewers and waterways of trash buildups. In return the warren to the north of town is tolerated and rarely decimated. That's the one issue that keeps them from becoming respectable taxpayers, the savage nature that bursts forth if population levels built up too far. Unlike the Drow, who've learned to fit in to the full society, the Skaven tribes still have not figured out a method of internal control. There are a few Skaven families who pay taxes and function as go-betweens, selling the fertile mulch and gleanings from the trash hauling. They live a life of double danger, squeezed by the ferocity of the Skaven hoards on one side and the mistrust of most of the other races they do business with. Still, it's a living and a niche that has to be filled.
Many different folks ended up settling in T'Ell, moving from the Empire and its somewhat restrictive laws to the lower restrictions of the free-port. Magic is fairly lightly regulated, for example. Across the river in Velchea there's a very rigid guild structure with dues and lots of regulation. Per capita more mages, sages and alchemists live in T'Ell than anywhere else, if any sort of accurate census could be taken. As the tax rolls are never released for perusal that data was likely never going to see the light of day.
Retired adventurers and a few active ones stay in town as well, either passing through on business or resting up between jobs. There are residence Inns, places for rent or rarely a place to buy. Land doesn't turn over often in T'Ell as it's all fairly well utilized. Over the years T'Ell has grown to a three-dimensional jigsaw puzzle of spaces. In fact, new excavation requires permits and study to prevent encroachment on existing spaces or risking a collapse. Everyone wants to be within the bounds of the free-port if possible, for the tax and legal advantages usually.
There are many discrete services and shops within the city that most would never need to see or utilize. But if you have a need, there's this guy who knows a guy...