Point zéro des routes de France

"Just outside of Notre Dame Cathedral embedded in the concrete of the public square is a small geographic marker from which the distance from Paris to all other places are judged. But rather than some dry symbol of measurement the spot known as Paris Point Zero has attracted a surprising number of local rituals. One of a number of so-called “kilometre zeroes” around the world, Paris Point Zero marks the supposedly exact center of the city or country. All other locations are thought to be measured as a distance radiating from this point. Paris’ center is marked by an octagonal brass plate that is set rather unremarkably into the concrete of the square. due to the marker’s low profile, some visitors have a hard time even finding it, but often times when they do, it has become customary to pay respects in any of a number of ways. Many of the customs performed on the site, are of the wish-granting variety, be it spinning in a circle on one foot atop the marker to gain your heart’s desire or kissing a loved one above the plate to ensure a eternal devotion. Sometimes the slightly concave marker can even be found to be filled with coins thanks to the popular tradition of using the point as a sort of wishing well. Others still pay pilgrimage to the site when they feel that they have experienced Paris to its fullest, using it as a proverbial period in the story of their journey. Undoubtedly there are countless other rituals of devotion to the very heart of Paris, but however it is expressed, this geographic marker likely receives more love than most around the world.  Update May 2019: Because of the fire of Notre Dome Cathedral in April 2019, this location is now inaccessible and may be for a while." - ATLAS_OBSCURA