 Cities are the heart of modern civilization. They house the seats of governments for most countries, administrative centers for businesses, transport hubs, and in the modern era, the majority of the human population. If you're making a fictional setting, whether it's fantasy, sci-fi, or something else, you're probably going to have to include multiple cities in there somewhere. But you can't just pick a spot on a map and put a big settlement there. There has to be some reason for it. A city doesn't pop into existence on accident, and it isn't just a collection of buildings either. So if you want to learn more about how to make a well-put-together fictional city, keep watching. If you don't, then why not watch one of my many other videos? Please. I want you to look at the maps of all these major cities and see if you notice anything that they have in common. Do you have it? They're all along a river or the coastline. And the reason for that is simple. Trade. The main purpose of cities is economic. They provide a central place for commerce. Farmers and herders trade food for manufactured goods like clothes and tools. The dense population and infrastructure of a city allows for people to specialize in different jobs, which are needed for a complex society to exist. Imagine if you had to make your own food and clothes. Modern life wouldn't be possible. In modern society, the majority of businesses exist in cities because they want to be close to other businesses so that they can work with one another. And in ancient times, the best method of transportation by far was sailing. It was faster and safer than overland travel, and even a medium-sized ship could carry way more cargo than a dozen mules and horses. So cities usually had to be on the water in order to facilitate trade. And even in the modern day, shipping by water is often cheaper than other methods. There are exceptions to this rule, of course, but major cities that aren't on the water usually popped up as a result of being centrally located along land trade routes. Denver and Mecca are both examples of this. When people are forced to trudge along on land, they need places to stop and rest. And when multiple groups of them stop at the same place, they trade with one another. Soon enough, some more infrastructure gets built up and the area becomes a city in its own right. Now, you might be building a setting with more advanced technology. Maybe it involves people colonizing planets and other solar systems. If that's the case, then water will probably be less crucial to the infrastructure, but you still need to take into account the sorts of infrastructure that people used to travel to and from the city. Let's imagine that someone founds a city on Mars. We'll call it Bruno. The primary method of traveling away from Bruno is on monorails powered by sick beets. They wouldn't want to build a city on top of a mountain. It would make building the monorails more difficult and going uphill would require them to use up more of their limited musical fuel. It would be much easier for them to build on open, flat land. Another thing to take into account when looking at a city's placement is what sorts of natural resources are nearby that it can take advantage of. Tying into water is fish, which can be a great source of food for communities. Then there's things that settlements can build their economies around like iron, good cropland, coal, magic stones, or whatever else happens to be valuable in your setting. Ideally, the city should be near some sort of resource, but not right on top of it. That way they can control it, but not have all their houses and roads get in the way of extracting it. So basically, don't just pick a random spot on the map and decide that a city should be there. I'm looking at you, Kamen. With cities being a hub of wealth and administration, they also tend to become a target of hostile military forces. Many of the most famous battles and sieges in history took place in or near cities. Capturing them can also mean capturing resources, infrastructure, fortifications, and sites of religious or political significance. Because of this, ever since cities have existed, the people in them have built defenses to protect themselves. The most obvious and common type was a wall. Just build up a bunch of bricks and it prevents armies from getting in easily. A small number of people on a wall can defend from a much larger number of people on the ground, since those on the ground would need to somehow climb the wall, break through the wall, or break in through a gate. It wasn't uncommon for there to be multiple sets of walls either. That way if the enemy was able to get through the outer wall, the people could retreat behind the inner walls. And oftentimes there was an ultra fortified position called a citadel that protected the most important parts of the city. Usually this was the homes of the ruling class, and in some cases it was used to defend from both outside attacks and peasant rebellions. Citadels had walls, but also included things like castles and moats to make them even harder to take. So it was almost always able to hold out longer than the rest of the city during sieges. Sometimes in addition to all of this, the city would be laid out in a way that favored the defenders. The streets could have been narrow and winding so that attackers would become disoriented and wouldn't be able to bring their full force to bear. The defenders could let the attackers into open areas and fire at them with archers or something. Urban warfare has always been a nightmare, and you should feel free to use your imagination to make it even worse. However, the importance of static defenses drops significantly as technology becomes more advanced. Once gunpowder was invented, attackers could just use cannons to pound stone walls to dust. Once bombers were invented, they could fly over the walls and drop explosives on the people inside. So in the modern era, defense depends more on having a mobile army that can move to intercept attackers. Fortifications are only really useful on a small scale. A wall or trench might not protect you from artillery, but it can protect you from a group of men with rifles. Once technology reaches a certain point, focusing all of your resources on something that can't be moved is no longer worth the cost. The only exception to this should be something that also has offensive capabilities. Think of the Mack guns from Halo. They're gigantic rail guns that can fire from a planet into space, and so any enemy fleets that come close enough to attack will get blown to bits. A lot of science fiction has similar technology, like giant lasers or nuclear missiles. These are all basically just big weapons that act as both swords and shields, if that metaphor makes any sense. If you have magic in your setting, then this might have the same effect. A wizard who's able to summon earthquakes won't be stopped by a wall. If that's a threat to the people of the city, they would most likely come up with some sort of different countermeasure, like magical wards or even just paying off their enemies to leave them alone, which happened a lot during history. There are more types of defense than just man-made ones, though. Sometimes the city proper was built on top of a hill so that any attackers had to climb upwards before they reached them. If there are any forests or other cover nearby, it was removed to prevent attackers from having any. There's also the matter of the water. Since, like I said, most cities are along a river or a coastline, that's very much a double-edged sword. Obviously, men and horses can't charge at you from across a harbor, so at least part of your perimeter is safe. But that leaves you vulnerable to attacks from ships, and therefore you need your own navy to defend yourself, or at least some sort of ranged weaponry like cannons. And if you don't have any of that, then your attackers can just hop in some boats and go around all of your fancy land-based defenses. Venice is one of the best real-world examples of this. In its early history, it was connected to land by marshes that were difficult to cross on foot, so any army had to come at it from the sea. But the Venetians prioritized building a navy, and consequently they got really good at sailing and shipbuilding. Almost no one could match them, which meant that almost no armies could even reach Venice to attack it. But even if they could get past or destroy their navy somehow, they would have trouble taking the city. Since it's actually made up of a bunch of small islands, the people got around using canals that would have been far too narrow for big battleships to navigate. So any amphibious invasion would still have to stop near the edge of the city and let their infantry try and navigate that mess. In the era before gunpowder, Venice might have been the most well-protected city in the entire world. Of course, now that I've said that, I fully expect about 800 comments telling me that I'm wrong and that I should kill myself. In fiction, this can be made a million times better or worse. If there's a race of sea people that can breathe underwater, then they can probably attack from the water without boats. If a wizard can dam the river downstream, then they might be able to flood the city without fighting at all. The trick to making this sort of thing logical is to just think about what sort of threats the city might face and then think about what sort of countermeasures the people might have for that. Of course, keep in mind that a lot of these are expensive as hell, so if the city doesn't have money, then they could very well not have proper defenses. We all need food to eat. I don't think that's news to anybody. And cities, for the most part, can't make their own food, which means they have to have some sort of relationship with the surrounding area. Towns and villages and farmsteads tend to cluster around cities, since the bigger settlements act as centers for government and commerce. These smaller settlements will produce food or other resources in exchange for goods that they can't produce themselves. This symbiotic relationship requires many towns and villages to support one single city. This also means that food tends to be more expensive in urban areas. The cost of packing, preserving, and transporting it has to be tacked on in order for a profit to be turned, at least in a capitalist society. If something happens to cut the city and the country off from each other, then they're both in trouble. The city will quickly run out of food without an influx of it. Historically, this is why they would usually have stores of food on hand, in case there was a siege or a bad harvest or something else to that effect. The towns and villages will be alright on their own for a while, but eventually they'll run out of things like tools and if an army comes for them, they'll have no one to turn to for help. How much food can be brought in tends to restrict the size of any settlement, but especially cities. If a lot can be brought in, then the city can grow and expand. This often means building more homes and streets outside the current boundaries and even building more defenses, like another wall, for example. The downside is that this is obviously very, very expensive, both to build and to maintain. So a wealthy city can grow while a poor city will often shrink. If you want to make a city that's more independent from the surrounding area, then there has to be an excuse of some sort. Maybe there are large gardens inside the walls that they use to grow food, or maybe they can turn rocks into food, like in the Stormlight Archive. Use your imagination, there's plenty of ideas out there that haven't been tapped into. Keep in mind that all of this is true no matter what the technology level of the setting. New York and San Francisco don't make their own food, just like Lakeside, Colorado isn't making its own cars, guns or computers. And this all ties into the next part. So how big should a city be? In theory, there's no limit to how big a city can grow as long as business and government can keep up with the increased complexity. In practice, though, that increased complexity tends to put a limit on city size based on the available technology. In 2019, Paris has a population of over 2 million people. A thousand years ago, there were barely 20,000 people living there. Because of slow transportation and lack of refrigeration, food couldn't be taken from all over France like today. And since there was a lack of things like sewage systems, indoor plumbing, and modern medical care, disease was rampant. Not that it wasn't rampant all over the place, just that it was worse in places with dense populations. And the more people that are packed together, the worse the problem gets. With proper sanitation, the problem is no longer as big. However, to get proper sanitation, you need to have a functioning local government. There can't just be one noble with some soldiers, there have to be planners and workers that keep things clean. And then there are problems with things like traffic and tax collection. Bureaucrats and rules are needed for cities to run properly. If they don't have those, then they won't be much more than slums. And if that's what you want to create, then go right ahead. Just keep in mind that the population's ceiling is lower in that case. And again, this is something that becomes less pronounced as technology advances, but there still needs to be some level of proper management to keep things running smoothly. Cities are the center of human civilization, so it's going to be almost impossible to build any sort of setting without including them in some way. And if you're one of those people that spends every moment obsessing over worldbuilding like I do, then hopefully this video was helpful for you. And if you're not, then why the hell did you watch this far? At some point in this, you might have been thinking that there was some overlap between this subject and the subject of my last how-to worldbuilding video. And yes, yes there is. That's really the secret to good worldbuilding. Remembering that everything is connected. Economics affects how wars are fought, wars are influenced and are influenced by religion. Religion affects how and what people eat. The list goes on. So if you take nothing else from my channel, take this piece of advice. Everything ties into everything else. Change one thing and you'll change everything else. Also, subscribe. Special thanks to all of my patrons who voted on this topic. If you want to participate in polls to determine future topics, then check out my Patreon page down below. Bye.