Maps are mirrors. They are designed, at the most elementary level, to translate vast geographic space into something compact, yet they can’t help but reflect much more: ignorance, fear, prejudice, fantasy, myth. Two famous ancient globes embrace the unknown with the words Hic sunt dracones: “Here be dragons.” Even Google Maps and Waze trade on what we all know to be speculation—the idea that they’re sending us on the best route.

Many maps are deliberately fanciful; see, for instance, Huw Lewis-Jones’s The Writer’s Map: An Atlas of Imaginary Lands. Call it crypto-cartography. A few years ago, while visiting a friend at the British Museum, I saw outside his office a magnificent framed print of an island. It looked from a distance to be very old, but upon inspection it was a brilliant pastiche of an invented place: a mental map that captured the stream-of-consciousness outlook of someone in modern Britain. In a neat, 16th-century hand, it designated villages such as Chattering, Bespoke, and Them; a lake called Delirium; a beach named Neglect.