How Did the Romans Map Their Empire?

And why didn’t their maps look like ours?

If I asked you to imagine the Roman Empire, you’d probably envision something like this:

By Thomas Pusch, CC BY SA 3.0

It’s an image that hangs in countless history classrooms (or occupies a slide in teachers’ PowerPoints, at least). The Roman Empire, for some reason always salmon-colored, clearly delineated on a map. The boundaries of…