To worldbuild a fantasy city, start from why it exists in that exact spot, because a real city sits where water, defensible ground, and a trade crossing meet, and everything else grows out of that reason. Build the districts from who lives where and why, decide how the place feeds itself and moves people and goods around, and give it a few sensory specifics rather than a gazetteer. In a long web serial the hard part is not inventing the city but keeping it the same city across hundreds of chapters, so the streets, factions, and landmarks a reader remembers stay where you left them.
How do you worldbuild a fantasy city?
You worldbuild a fantasy city by deciding why it is there before you decide what is in it, because the reason a settlement exists is the thing that makes every later choice cohere. The way this usually goes wrong is familiar to anyone who has read a lot of web fiction: the author needs the heroes to reach the capital, so a capital appears, and it comes furnished with a market district, a noble quarter, a slum, a tavern with a colorful name, and a palace on a hill, all of it assembled because those are the parts a fantasy city is supposed to have. Nothing in it answers the question a real place answers without being asked, which is why anyone chose to live here in the first place. Cities are not decorations that spawn where the plot needs a backdrop. They are the accumulated answer to a practical problem, and if you know what problem your city solves, the districts and the walls and the wealth stop being a checklist and start being consequences.
Historians have long pointed out that people settle where three things overlap: fresh water they can drink and travel on, ground they can defend, and a place where trade naturally has to pass, a river mouth or a ford or a mountain pass or a sheltered harbor. That is the same terrain logic that shapes the whole map, and it is worth building your continent first so the city has somewhere to sit, which is exactly what I lay out in the companion piece on how to make a fantasy world map. The map sets the region and the trade routes; the city is the knot where those routes tie together and people decided to stay. A city is only one of the systems a serial world has to hold together, alongside its magic, its factions, and its economy, and I build all of them with the same start-from-the-forces approach that runs through the broader guide to world-building for web fiction. My feeling is that if you can answer "why here and not five miles upriver," you already know more about your city than most fantasy capitals ever reveal.
Put the city where geography and money would put it
A believable city sits at the intersection of a resource and a route, and its wealth comes from controlling that intersection. Think about what the place does for a living before you think about how it looks, because the economic reason for a city being rich or poor, growing or decaying, is what fills its streets with a particular kind of person. A port city that taxes everything moving through its harbor grows a merchant aristocracy, a customs bureaucracy, warehouses, smugglers, and a dockside underclass, and those groups are your factions before you have named a single one. A fortress city guarding a mountain pass grows a garrison culture, a supply trade, and a population that has learned to live under a soldier's rhythm. Scott Lynch's Camorr in The Lies of Locke Lamora (2006) is a canal city built on the drowned glass of an older civilization, and almost everything memorable about it, the boat traffic, the floating markets, the vertical layers of rich and poor, comes from that watery geography rather than from decoration laid on top. Fritz Leiber's Lankhmar, the archetypal fantasy city that the Fafhrd and Gray Mouser stories built across the mid-twentieth century, is fog and thieves' guilds and commerce precisely because it is a great trading port left to rot at the edges.
The trap I see most often, running a web fiction platform and reading a lot of early manuscripts, is the capital with no visible means of support: a huge city in a place with no river, no harbor, no farmland, no reason, existing only because the emperor lives there. Real capitals sit where they sit for a reason that predates the throne, and the ones that were founded by decree, planted in the wrong place by a ruler's vanity, tend to be expensive, artificial, and interesting precisely because everyone knows they should not be there. You can use that. But you have to know you are doing it, rather than dropping a metropolis onto empty ground and hoping no reader asks the obvious question.
Build districts from who lives where, and why
Districts are not zones on a map, they are the physical residue of who has power and who does not. Wealth in a real city clusters on the desirable ground, which usually means the high ground, the upwind side, the land away from the tannery and the slaughterhouse and the flood-prone riverbank, and poverty gets pushed to whatever is left, the low ground, the downwind reek, the edges that flood. That single gradient, desirable ground versus undesirable ground, generates a social geography without you having to invent one, and it gives you conflict for free, because the boundary between two districts is where the frictions of the whole city rub together. Brandon Sanderson's Mistborn (2006) builds Luthadel almost entirely on this axis, the noble keeps and the skaa slums separated by more than distance, the falling ash settling on everyone but meaning something different depending on which quarter you sweep it from.
The move that makes districts feel alive rather than color-coded is to give each one a want and a grievance, the same way you would a character, which is why the craft of a city and the craft of a cast rhyme. A guild quarter that resents the harbor tax, a temple district quietly funding one faction in a civil war, an old-money hill that despises the new-money merchants climbing toward it: these are the fault lines that turn a static backdrop into a place where things can happen. Terry Pratchett's Ankh-Morpork across the Discworld books is the masterclass here, a city held together by the barely-contained self-interest of its guilds, its watch, its patrician, and its mob, so that any story dropped into it immediately has something to push against. You do not need Pratchett's decades of accretion. You need two or three districts that want incompatible things, and the seams between them marked on your own map.
Decide how the city eats, moves, and is governed
The detail that separates a real city from a stage set is the machinery nobody usually writes, because a city that cannot feed itself, water itself, and haul its own filth away is not a city, it is a diorama. A pre-industrial settlement of any size cannot grow its own food inside the walls, so it depends on a ring of farmland and a constant stream of carts and barges bringing grain in, which means your city's true size is capped by what the surrounding land and the water supply can sustain, and its most vulnerable point is the road or river that feeds it. Cut that, and you have a siege plot without inventing anything. Rome ran aqueducts for miles and a state grain supply to keep a million people fed and watered, and the reason those systems are famous is that they were the load-bearing miracle that let the city exist at all. You almost never need to explain any of this on the page. You need to know it, so that when a character walks to the market the bread came from somewhere, when it rains the streets do something plausible, and when an enemy wants to break the city they go for the granaries and the water rather than the front gate.
Governance works the same way, as a thing you feel rather than a lecture you deliver. Someone collects the tax, someone keeps a rough order, someone decides who is allowed to sell in the square, and the shape of that authority, a council of merchant houses, a hereditary lord, a temple, a criminal cartel that runs the docks in all but name, tells the reader more about the place than a paragraph of history ever will. China Miéville's New Crobuzon in Perdido Street Station (2000) is unforgettable largely because its grinding, corrupt, militia-run government is present in every scene, pressing on the characters, rather than existing as a footnote. Pick the one or two mechanisms your plot will actually touch, make them concrete, and leave the rest implied.
Make it feel lived-in without writing a gazetteer
A city feels inhabited through a few precise, working details, not through a comprehensive tour, and the difference between the two is the difference between fiction and a travel brochure. The instinct to prove how much city you built by describing all of it is the fastest way to kill the very aliveness you are after, and the discipline of getting a setting onto the page through scene and sense rather than exposition is its own craft, which I go through in detail in the piece on how to reveal worldbuilding without infodumping. For a city specifically, the details that carry the most weight are the ones tied to what the place does for a living: the smell of the tanneries when the wind turns, the particular call of the fish auction at dawn, the way the rich district's gutters run clean while the low quarter's do not, the coin that is worth less three streets over. One working detail that implies a whole system beats ten decorative ones that imply nothing. Pirateaba's The Wandering Inn, an ongoing web serial, makes its walled cities feel real less through description than through the accumulation of ordinary business happening in them across hundreds of chapters, so that by the time something threatens a city the reader has watched it live and therefore cares.
And that accumulation is the real challenge of a city in a serial, because a city you use once can be held in your head, but a city your characters return to across a year of updates cannot. The fifth time the crew walks through the harbor district, the tavern needs to be on the same street, the guildmaster needs to hold the same grudge, and the landmark you described in chapter forty needs to still be standing in chapter three hundred, or a returning reader will feel the ground shift under them. This is where a city stops being an act of imagination and becomes an act of bookkeeping.
Keep the city consistent across a long serial
The way a recurring city survives a long web serial is external memory, a single place where every district, landmark, faction, and named local lives so you are consulting a record rather than trusting your memory three hundred chapters in. This is the part of world-building that a tool built for serialization actually earns its keep on, and it is why the connected wiki inside the IlorisNovel editor is designed as a relationship canvas rather than a static notes file: you can give each district and each landmark its own entry, note which faction controls the docks and who they are feuding with, @mention that guildmaster in a chapter so the reference is linked back to the entry, and use the timeline to log the fire that gutted the market quarter so it stays gutted in every later scene. None of that is glamorous, and none of it appears on the page, but it is the difference between a city that stays solid under a reader's feet for a year and one that quietly contradicts itself until the place stops feeling real. I think most authors underestimate how much a long serial punishes a world held only in the head, and how much a returning reader rewards one that holds.
Build the reason first, then the districts that grow from who holds power, then the plumbing that keeps the place alive, and only then the handful of sensory details that let a reader stand in it. Do that much and your city will already outclass the furnished-backdrop capitals that make up most of the genre, because it will answer, in every scene, the question those cities never can, which is why anyone chose to live here at all. The rest is upkeep, and upkeep is a solvable problem in a way that imagination is not.
by Jacob Tam · September 25, 2026
I run IlorisNovel, a platform for web fiction writers. If you want to see what building a world here feels like, you can try the editor with no account.