A good street is like a river. Rue Saint-Denis flows through the history of Paris. It’s a segment of an ancient trade road that dates from the Bronze Age—a thoroughfare for merchants and pilgrims working their way up and down the French peninsula between Spain and England. A historic street, it winds its way down, from the top of Paris, Porte de la Chapelle, to the middle of the city, Place du Châtelet. Its course coincides with the north-south axis of the Roman cardo, the Via Agrippa.

Countless feet, hooves and wheels have carved the path of Paris’ oldest street. Still relatively narrow, rue Saint-Denis feels like a riverbed, with many tributaries feeding into it.: some are bucolic alleys, others are slightly seedy lanes, while still others are nostalgic skylit galleries with old-world elegance.

A good street is like a river: it carves its bed through layers of history. (Upstream: rue de Faubourg Saint-Denis)

A good street is older than the city it runs through. You can follow it downstream, all the way to Spain. (The Porte Saint-Denis is the gateway into medieval Paris.)

A good street has many tributaries: side alleys that meander around backyards. (A private lane, upstream.)

Remarkably un-gentrified, rue Saint-Denis provides the kind of urban habitat that breeds diversity. Ethnicities and social classes coexist peacefully, some more dominant than others depending on the hour, the season, or the day of the week. North of the arch, the rue du Faubourg Saint- Denis, as it’s called upstream, is a bazaar: sharing the sidewalk are Pakistani motorcycle enthusiasts, African jewelry makers, Chinese food vendors, and moms pushing strollers.

South of the arch, the oldest profession in the world is practiced openly on some corners—this section of the rue Saint-Denis is not a tourist destination and few Parisians venture there after dusk. Let’s just say that cool hunters, fashionistas, trendsetters and foodies have yet to discover it. The rest of us embrace it all.

A good street has sheltered coves. These traffic islands are popular with gawkers. (Sketching in the shadow of Porte Saint-Denis.)

A good street lets you navigate between sun and shade. (High noon.)

A good street has corridors where kids can play. (Passage du Caire)

People can’t help but spill all over good streets. (Ten o’clock on a summer night, rue Saint-Denis)

A good street has arcades, slightly seedy, but still fancy. (Passage Brady, one of the street’s most famous skylighted passages.)

The flâneur that I am relishes sneaking into courtyards, peering through gates, and exploring the maze of alleys, arcades, and galleries.

Everywhere you look, someone from the past has a story to tell. Dominating the narrative are a saint, a king and a philosopher.

First Denis, the Christian martyr who gave the street its name. Avatar of Dionysius, alias Bacchus, he is the patron saint of Paris, a city known for its libertine ways. Looming large as well is king Louis XIV, for whom the monumental Saint-Denis arch was built — just I Qme for his funeral procession. Most intriguing is Walter Benjamin, the German philosopher and art critic who, upon studying the street’s covered passages and its shopping galleries, predicted the advent of the consumer culture.

Rue Saint-Denis, your feet guide your thoughts.

A good street has secrets. Legends, folktales and ancient memories flow through it. (Detail of a bas relief on Porte Saint-Denis)

A good street’s pavement is worn to perfection. (Passage de la Trinité)

A good street provides small eddies of serenity along its banks. (Evening rush hour rue du Faubourg Saint-Denis)

On a good street, sunlight bounces around, reflected from the most unexpected angles. (Passage du Caire, the oldest covered indoors/outdoors street in Paris)

A good street is like a river. It flows placidly through wildly different landscapes. (Before dusk, in the heart of the red light district)

All photos by the author.