On the southern edge of Paris, a five-thousand-square-foot basement houses the city’s lost possessions. The Bureau of Found Objects, as it is officially called, is more than two hundred years old, and one of the largest centralized lost and founds in Europe. Any item left behind on the Métro, in a museum, in an airport, or found on the street and dropped, unaddressed, into a mailbox makes its way here, around six or seven hundred items each day. Umbrellas, wallets, purses, and mittens line the shelves, along with less quotidian possessions: a wedding dress with matching shoes, a prosthetic leg, an urn filled with human remains. The bureau is an administrative department, run by the Police Prefecture and staffed by very French functionaries—and yet it’s also an improbable, poetic space where the entrenched French bureaucracy and the societal ideals of the country collide.

Parisians d’un certain âge know the street on which it is located by name. “Ah yes, on Rue des Morillons,” they’ll say wistfully when the bureau is mentioned, a hint of melody to their voice. It is the street where the legendary French singer Georges Brassens once lived (a small park and vineyard abutting the building bear his name). The Bureau of Found Objects would have made an interesting subject for Brassens, whose lyric songs often railed against law enforcement (in his 1952 hit “Le Gorille,” for instance, a gorilla escapes from a zoo and sodomizes a heartless judge in his robes), or for his contemporaries Jacques Brel and Serge Gainsbourg, who often mocked French bureaucracy. Instead, it was Paul Braffort, a member of the Oulipo school and a close friend of Raymond Queneau, who wrote a surprisingly romantic ode to the bureau, titled “Rue des Morillons.” “Why don’t we open / Rue des Morillons / in that large stockpile / an aisle for all the lost hearts / for all the misplaced lovers / that are sent so gaily into oblivion?” he sings, in French, in seductive simple rhymes. “Those who may have lost / Love, joy, and even a little more / could then find each other / at the Bureau of Found Objects.”

It is with a similar hint of romance that many French people d’un certain âge embrace this mythical public service, though those in the younger generation, armed with smartphones and having never heard the song, often do not know of its existence.

At 36 Rue des Morillons, the waiting room is bathed in light, and appointed not with the plastic chairs of an American D.M.V. but with the heavy wooden furniture of a nineteenth-century courtroom. The vast majority of people arrive clutching envelopes. Whenever an item arrives containing a mailing address (for example, an I.D. card in a wallet) the bureau will mail a letter to its owner informing the person that it has been found. Like many French civil services, the bureau still conducts business mostly in person or through the post—tradition oblige. The bureau does not have a dedicated number to call; a lone employee is tasked with answering e-mails.

Alice Cavet arrived holding such a letter. She was assigned a number at the arrivals desk and, minutes later, was called to window F, where a woman handed her a red flower-patterned wallet. “Ah, mon Dieu, je n’y croyais plus!” she exclaimed—I no longer believed. She rushed over to the large wooden table and began to pull out her credit cards and business cards. She removed a small pouch and poured from it a metal trinket—an amulet of the Virgin Mary that her mother had gotten blessed for her at Lourdes.

Her wallet had been lost for ten months. She’d cancelled her credit cards, and had all of her I.D. papers remade. Her mother had bought her a new wallet, an exact replica of the red floral one but in blue. Still, a grin spread across Cavet’s face. “The money is no longer here, of course,” she told me, “But a girl’s wallet is filled with memories. The letter from a friend, the seashell from the shore, which must be . . .” She dug her fingers into a crevice. A tiny seashell fell out and rolled across the table.

Again and again, I noticed the same gestures repeated in this space. People checked their reclaimed items carefully, wondering at how their possessions, even after being lost, retained the markings of their private lives. A girl pulled handfuls of scarves and crumpled pages of homework out of an overflowing handbag. Two women marvelled that the contents of a recovered coat remained in place—a key ring, a handkerchief, a hard candy. An older man sat alone, turning a business card over and over between his hands before silently replacing it in his wallet and leaving. The unspoken rule of city life that only the crazy speak to strangers did not hold in this room. People struck up conversations easily, commiserating in the state of losing and seeking, or sharing in the joy of finding. “Je n’y croyais plus,” people said aloud, to themselves and to one another. “Look, Pierre!” a woman said to her husband, whose wallet had been pickpocketed at a Métro station. “This is the receipt from the day you lost it. This was the day you went out to do your shopping!” The mundane takes on significance when it is lost and then returned.

Around six or seven hundred items make their way to the bureau each day. Photograph by Keystone-France / Gamma-Rapho via Getty

An employee stooped to the floor to pick up a key ring on a length of rope. “A found object!” she exclaimed, as she returned it to its owner, who laughed, ashamed. The bureau’s director, Patrick Cassignol, told me that people who come to claim one object very often lose another in the process. Perhaps, he theorized, “L’émotion favorise l'étourdi”—emotion leads to forgetfulness. Or, perhaps, there are those who are simply destined to lose, a breadcrumb trail of belongings left in their wake.

One of the defining rights of a citizen of the French Republic is the right to the ownership of property. Before the French Revolution, ownerless objects—referred to then and now as épaves, or “flotsam”—belonged to the lord on whose land they’d been found. This applied equally to the cargo discovered aboard shipwrecks. In the late sixteen-hundreds, an edict stipulated that lost objects be announced by a herald outside the church so that their owners might have the chance to reclaim them. Still, the laws overwhelmingly favored those who possessed the land over those who possessed the objects lost upon it. That changed in 1789, when the French Revolution abolished feudalism. The Declaration of the Rights of Man and of the Citizen stated boldly, “Property is an inviolable and sacred right . . . It is man’s property that makes of him a man, and not a subject, a machine, an animal, that makes of him a citizen before the law.” It is no coincidence that this shift coincided with the industrial revolution. Before, people had few belongings, wore the same clothes for weeks, and rarely misplaced them. With the advent of more personal possessions, people, in the words of the poet Elizabeth Bishop, “practiced losing farther, losing faster.”

It was under Napoleon, in 1804, that lost objects began to be centralized at the headquarters of the Police Prefecture, and not long after that the Bureau of Found Objects was officially formed. In Anglo-Saxon common law, lost objects are still governed by what is colloquially referred to as “finders keepers”—property belongs to the one who possesses it, unless evidence is provided to the contrary. But, in modern France, man’s uninterrupted right to his possessions, even his misplaced ones, is one of his most basic. The bureau sees as its guiding mission not only to return objects but to return them only to those who can prove their ownership.