While working on some example region contents for Manteu, I tried to lean into my keying mantra, a principle so simple as to be obvious, but which is easy to forget. "What is the most interesting thing that could be here?" If your setting could have Dracula, put his castle in a place it might be found. If your setting has a pope, put her on the map. If your setting emulates some genre, encode places and situations where the cool stuff of that genre can show up.