Notre Dame Cathedral, which is set to reopen to the public on Sunday after a five-year restoration following a devastating fire, stands as a jewel of Gothic architecture, a symbol of Paris and a tourist mecca.
But behind the grandeur of the cathedral, which took 182 years to build between the 12th and 14th centuries, lie some surprising stories. From medieval myths to modern-day mysteries, here are five special things to know about this Paris landmark:
Notre Dame's importance goes beyond its architecture and history — it's literally the point from which all roads in France begin.
In front of the cathedral, embedded in the cobblestones, lies a modest bronze-and-stone slab with the inscription "point zéro des routes de France," meaning "starting point of the roads of France.'' This plaque marks the starting point for measuring distances between Paris and other cities across the country.
While the plaque was installed in 1924, the idea of a national "ground zero" dates to 1769. King Louis XV envisioned a central reference for France's growing network of roads, a concept that tied the nation's geography to its heart in Paris.
Those scary stone creatures on Notre Dame might seem ancient, but not all of them are what they appear. The actual gargoyles, which are monster-shaped gutters used to drain rainwater, have been around since the time of the cathedral's construction. But the dramatic, monster-like figures often depicted on postcards and movies are chimera, and they're much newer.
In the 19th century, the architect Eugène Viollet-le-Duc, who was in charge of renovating the then-decaying building, added these creatures to add to the mystique of the cathedral. Viollet-le-Duc drew inspiration from Victor Hugo's famous book ''The Hunchback of Notre Dame'' to create these demonic animal figures with personified expressions.
How to tell them apart? Gargoyles resemble horizontal spikes coming out of the facade and have holes in their spouts to allow water to drain.
During the French Revolution, which saw waves of protest against the Church, Notre Dame wasn't exactly treated like a revered cathedral. In 1793, revolutionaries stripped it of its religious symbols and renamed it "Notre-Dame de la Raison" (Our Lady of Reason).
Instead, the cathedral hosted festivals celebrating science and Enlightenment ideas, and for a short time, it was even used as a wine warehouse.
Religious services resumed in 1795, and Notre Dame regained its sacred status on the impulse of French emperor Napoleon I, who held his coronation there in 1804, immortalized in a famous painting by Jacques-Louis David.
In 1792, revolutionaries also decapitated 28 statues from Notre Dame's facade, mistaking them for French monarchs. They were actually ancient kings of Judah, biblical ancestors of Jesus. The heads were thought lost forever, possibly destroyed or sold as building materials.
But in 1977, workers renovating a courtyard in Paris' 9th arrondissement uncovered hundreds of fragments of stone sculptures. Experts confirmed they were the missing heads of Notre Dame's kings. How they ended up buried there remains a mystery.
Today, 22 of the heads have been restored and are displayed at the Cluny Museum in Paris. Their discovery is considered one of the most remarkable archaeological finds in the city's modern history.
The 2019 fire that almost destroyed Notre Dame revealed a serious health risk. When the flames melted the roof, tons of toxic lead dust were released into the air and settled across Paris.
The problem? Authorities discovered there were no rules to measure the danger of outdoor lead dust. This wasn't just a Paris issue — major cities like London and Rome, and even the World Health Organization, don't have guidelines for outdoor lead pollution.
The Notre Dame fire highlighted a hidden problem, forcing officials to take a closer look at their safety standards. It took four months for the city to complete a deep-clean operation of the sidewalks even as tourists, residents and merchants walked streets around the cathedral daily.