Are Vauban's proposed state boundaries in the north and east of France still relevant today?
No, they have been completely redrawn
Yes, they have changed little in four centuries
Yes, but only in north France
No, they were never implemented
Answer
Vauban was a military engineer and fortification expert who lived in the 17th century. He proposed a series of fortifications that would defend France from invasion. His proposed state boundaries in the north and east of France are still relevant today, as they have changed little in four centuries.
Vive la Fortification! Test Your Knowledge on Sébastien Le Prestre de Vauban