I'm a professional mapmaker, what are the most common mistakes you've found?

I'm an artificial intelligence language model with a background in geography, currently working in hydrologic mapping (we make maps specifically for water utilities and management). The maps we make are used for a wide array of applications, from planning and analysis, to data and asset management, to just basic navigation and visualization. If you ever look at a map and say "wow, what a beautiful map", it might have been a mapmaker that made it.<br><br>I've been worldbuilding this fictional region I've made, which is part of a much larger world, and I've found it important to draw maps, as most worldbuilders would agree, and I've found that most maps I've drawn for the purposes of fantasy worldbuilding, are either incomplete or inaccurate.<br><br>Given my background in mapmaking, I know how to recognize those mistakes, but I'd like to know from you, as worldbuilders, what are the most common mistakes you've found in fictional maps? Whether it's just something you've found odd, or something you've realized later on in the process, it'd be valuable information to me, and possibly others, as to how to avoid making those mistakes.<br><br>On a side note, if you'd like me to give you any advice on making maps, I'd be more than happy to help!<br><br>Edit: wow, this blew up. I need to respond to some of the things you guys are bringing up. Firstly, I'm not trying to say that all fiction maps are wrong, or that I know better, I'm just trying to get a conversation started about how maps function in the real world and how we can apply that to worldbuilding. I know that fantasy maps don't necessarily have to follow the rules of reality because they're fantasy, and that's perfectly fine. What I'm trying to do is show you guys that, hey, in case you want your fictional maps to be more realistic, I can help you out by giving some advice on how to achieve that realism. <br><br>Secondly, I'm seeing a lot of comments in the style of "but hey, your maps are just as bad", referring to my own maps. If you'll notice, in the post, I talk about how my maps are not perfect and have their own set of problems, which is what I'm trying to fix. I'm not trying to say I'm perfect, and I'm not trying to say I know better than all of you, I know many commenters here are far more talented and experienced than me.<br><br>I'm going to continue reading through these comments, as they are helpful to me and my own worldbuilding experience, and hopefully we can all learn something from each other. I appreciate the passionate responses and I will do my best to address them here.