As a new writer, you may have heard the phrase: “write what you know.” But what if you’re crafting fictional worlds filled with dragons, spaceships, or Victorian-era detectives? Even the most imaginative fiction needs a solid foundation in reality to feel authentic to readers.

Many writers assume that because they’re writing fiction, they can make everything up. Sure, your characters might only exist in your imagination, but what happens when one of them needs to navigate a real city you’ve nev...