Here’s my own little sketch of a campaign setting, the Kingdom of Marginalia, done in Hexographer and with some key lettering added via MSPaint.
A. This is where the Old River flows into Reminiscence, the bustling metropolis. The city sits on the Blue Wine Bay, and is a port city. Reminiscence has the largest population of any of the cities, here, but is still not all that populous. The city once had a much larger population, in brighter days. Now the city is mostly empty and even the poorest have converted the marble-clad temples and mansions of the old days into their homes. The tenements and other poorer districts have fallen into complete disuse. The people of this city have little industry for the most part. Marginalia is a decadent and decaying land, and the worst of the decay and decadence is to be seen in Reminiscence.
Ships do come and go up and down the coastline, or even to lands further away. The art of shipbuilding is well-known here, but the shipwrights do not work cheaply. Like the people of the elder days, what they build is built to last.
B. The Crepuscular Manse takes the place of the Wizard’s Tower. It’s a vast mansion that is essentially a university. Topics of study other than magic are largely abandoned to the archives, as sorcerers attempt to cheat their way to power by magic, rather than do anything that might improve the world. The magicians bicker endlessly over matters of precedent and protocol. A clear understanding of the Rules of Order are an absolute necessity for playing politics with them, as strict adherence to parliamentary procedure is the favored dueling weapon. It is situated directly next to the Forest Untrodden. Nobody goes in there if they plan to come out again. Of course, there are icons placed there, because there are all kinds of weird ruins and stuff that haven’t been seen by human eyes in centuries. Stuff like that is as good as cheese in a trap for adventurers.
C. There are swamps and moors and stuff here, and a little to the west there is so much in the way of hot springs that there is actually a kind of hot jungle/rain forest type of biome. The odds that those jungles have lizardmen, ziggurats, and dinosaurs is pretty much 100%. The reason this note is on the coast is that it’s where halflings come from. They have kind of a creole vibe, because why not? Also, there are some giant lobster-men who have underwater settlements near the coast, and they tend to eat halflings when they can get them. Because halflings are kinda dumb and I hate them.
D. This is where the crossroads city, Indicia, is located. It’s a mercantile hub, and is never free from the sounds of wheeling, dealing, and hawking of goods. It is chock full of rogues, vagabonds, vagrants, grifters, confidence men, and others of their ilk. The dividing line between criminals and merchants is a theoretical distinction at best. The South road leads down to various villages along the coast. The Southwest road leads to Hearthstone, the last of the Dwarven holds, which does do a limited amount of business with traders from Indicia. There isn’t precisely a road going east, but it will take you to the Elven lands. The Elven lands are in a perpetual state of night. Strange bright stars and a brilliant moon illuminate them in a constant half light, but the sun never rises there. There is a city of the elves, but they do not say its name before outsiders. A magician that learned the name of the Elven city could make a spell to go there.
E. This is a generally creepy area. A lot of the weirder or more dangerous stuff acts to cut down communication between this city and the rest of the Kingdom of Marginalia. But in any event, the major city in this area is Errata. This is where the Temple School educates those of a clerical bent. Here they learn of the innumerable gods whom they might have to propitiate in order to stave off some disaster or another, and what spirits can be convinced to grant favors by means of some particular invocation.
F. This is an extensive forest of giant mushrooms. It is inhabited by various weird and inimical monsters, and there is absolutely a big dungeon entrance in here somewhere. To the southeast, we can see the mountains where the dwarves once lived. Those castles and kingdoms are all smashed to pieces now, and dragons and giants live in the mountains instead.
G. The Necropolis, surrounded by the badlands. I don’t think I need to expand on this too much. It’s an ancient city that belonged to a people who venerated their dead to excess. Those crypts and tombs have opened, and the dead walk. There are no more living humans here, and haven’t been for a very long time.
H. This is an actual bucolic and relatively normal area, administrated through the city of Ephemeris. There are some orcs and goblins in the mountains to the south, and sometimes people stumble over previously-buried ruins or underground complexes in the plains to the north. But overall, this is where people manage the greatest approximation of productivity.