So far we’ve discussed the natural world (Part One and Part Two). That’s all well and good but a large part of cartography for world-building has to do with the civilized world and the way that humans have altered the landscape.
An important part of maps are borders. Traditionally, national borders tend to fall across easily-identifiable natural features - mountain ranges, rivers, valleys, coastlines. As we approach a more modern era and arbitrary delineations and peace treaties become more common, territories become more abstract - compare the borders of European nations, which just look like random squiggles on a map without geography for reference - with the american states - most commonly arbitrary lines using lines of lat/long as reference.
You may want to use different types of borders (shapes, sizes, colors) to represent different things - alliances, treaties, vassalage, etc.
Cities and Settlements
Settlements cannot exist in places that cannot support their population... except when they do. This is a general rule and not an absolute. 99% of the time a settlement will require a degree of self-sufficiency, particularly depending on your setting. It needs a ready supply of people, food, water and jobs. If any one of those things is lacking there needs to be an in-world reason to explain why the settlement exists and what it does to acquire the resource that it’s lacking.
A basic rule of thumb whenever placing settlements is the following: why did people settle this place over elsewhere? There must be something that makes a place worth living in. Most commonly this would be a valuable resource. If a settlement exists in the middle of nowhere (hello Las Vegas) there better be a good reason - it could have emerged from a monastery, it might be built over an oasis, or it’s a place of great religious significance. Using the above example, Las Vegas is a resort or entertainment city and has no resources of note and is even lacking in water.
Resources and cities are intertwined. If a useful resource has been discovered in an area you can bet that intelligent races have begun to exploit it in some way.
We’re all familiar with the common resources - we see them in resource-management games all the time: gold, wood, stone, gems, iron (not steel or brass, please don’t make that rookie mistake!), copper, etc. Try think of things other than metals, gems and wood. Think of less-common resources - what materials are your people’s clothing made of (cotton, wool, flax); how do they dye their clothing or create pigment for artists (chemical, ore, animal); what is used in their perfume (plant, animal); what herbs and greens are used in their cooking; what animals are domesticated… The list goes on and can be as exhaustive as you are willing to make it. Try to think of potentially useless resources and how inventive people might have come up with a means of exploiting what might be ignored in a region that might have more plentiful resources. This type of thinking also helps create a more unique culture that makes it appear more believable.
Times passes and conditions change. A city that might have emerged from the production of one resource might find the resource spent. What is the city to do now? It will either naturally dwindle as people move away and less children are born there. This will eventually leave the please a ghost town. Alternatively, it might switch to something else - maybe it has a good natural harbour that can be used as dry docks. Remember , services such as banking and manufacturing can be considered as resources when thinking of the purpose of a city. A city might not have any good natural resources, though it might offer a particular service that is highly valued, resulting in a steady source of income.
Not all resources can be found in all terrain and climate-types. This is more obvious with things like fish and wood, though is also the case for ores and minerals. Try do a bit of research beforehand and find where particular resources can be found in the real world and extrapolate from there. What follows is a brief list of where some ores can be found and in what relation to each other:
Conversely - what resources does a particular region lack? If good stone is sparse people are going to build with different resources (mud-bricks, wattle and daub, wood). Can the people of this area make do without the resource? What are their work-arounds? How do the people of this area acquire this resource if it is one of importance? Certain resources can make those fortunate-enough to have it in abundance very wealthy. Very quickly, in response to changing trends as they export it at a premium.
Below is a list of real-world resources that might be found in your world. The list is pretty exhaustive and does not make distinction between technological ages or climates - that’s up to you to decide as it’s your world. The list’s main purpose is to remind worldbuilders that there are a LOT of resources, not all of which are natural, and each of these could have a part to play into why a city is located in an otherwise inhospitable place.
REAL WORLD RESOURCES
Roads link cities and nations together and can be part of a larger trade-route system (like the Silk Road) and are vital in worldbuilding.
Roads appear naturally as people travel between certain areas. Dirt tracks become paths, which itn turn become roads, which may evolve into highways. Modern settings may create highways from scratch to help the economy of two cities.
Part One: The Bigger Picture
Part Two: Smaller Picture