The corner of Paris that Thérèse and her acquaintances inhabit is defined by darkness, grime, and boredom. And as such, the Passage du Pont-Neuf and its environs stand in stark contrast to the public amusements and grand baroque architecture that, for many, defined Paris in the middle of the 19th century. In two of his major novels that followed Thérèse Raquin] - The Kill (1872) and His Excellence Eugène Rougon (1876) - Zola investigated the wholesale changes that took place in Paris’s infrastructure between 1853 and 1870. These alterations were engineered by Baron Georges Eugene Haussmann, a civil engineer appointed to modernize the city on behalf of Napoleon III.
“Haussmannization,” as it has since come to be known, rested on a few major principles: expanding streets to permit light and prevent traffic blockages, creating long straight boulevards that facilitated city navigation, and setting up street lamps and public gardens to create a more pleasant and exhilarating atmosphere. The process took years, and resulted in many of the landmarks that contemporary visitors to Paris still enjoy, including an enlarged and renovated version of the Louvre Museum. Even the Paris Morgue, which Laurent frequents, was built as part of the renovations in 1863.
In light of this, Mme Raquin’s apartment can seem like a holdover from another era. And in a sense it is; located on the bank of the Seine, the real Passage du Pont-Neuf did not undergo any major renovations until 1912. “A flat, banal, ugly” thoroughfare was how critic Charles Augustin Sainte-Beuve described it in 1868. The street thus harkens back to a Paris filled with older architecture and deep, disturbing shadows: the Paris that Charles Baudelaire described in his morbid prose poems, Paris Spleen, and that Charles Marville captured in his photographs of crooked streets, endless cobblestones, and streams of filthy water.
But even under these less-than-ideal conditions, Paris had its dedicated on-foot explorers - “flaneurs,” to take the French name for these inveterate strollers. Zola - who once wrote to Cezanne of walking “some eight or ten miles" from Paris - easily fell into this category. It is tempting to classify Laurent and Thérèse as flaneurs, too, but it would be inaccurate; they may follow the same routes as true flauneurs, but they are motivated by desperation, not pleasure.
For a photographic record of this period, the Second Empire website hosted by Mount Holyoke provides many helpful images.