There's a Map That's Been Accurate for 200 Years - Apparently.
The Carte de Cassini, a detailed map of France, was first published in 1815. Created by French cartographer Pierre-César Possel, it was astonishingly accurate for its time, with some estimates suggesting that its margin of error was less than 1 kilometer per degree of latitude. The map was so precise that it remained the official map of France for over a century, with many of its features still visible on modern maps today.