If you look closely, you can barely discern the carving on this compass rose that says "point zero." Stand on this spot in front of Notre Dame and you will be in the official center of the city of Paris, the point from which all distances to and from Paris on national highways are measured. Forget that this spot no longer (if it ever did) actually marked the midpoint of population dispersion or the city's physical space. It's all about the symbolic importance of the spot. But here's a handy tip. Street numbers in Paris use this as a reference point. That is, a small number will be closer to this point than a high number, and that's true for both north/south and east/west axes. After that, however, all bets are off.