Gaze at the bureaucratic monstrosity of the Tour Montparnasse, or the chaotic vortex of Citroëns that is Etoile, and you'll find it hard to suppress a little hiccup of nostalgia for the Paris of old – the city of quaint neighbourhood markets and horse-drawn carts familiar from belle époque art. Yet, as we all know, memory is an unreliable beast; and so, to determine once and for all whether the 20th century has been kind to the capital, we're presenting you with cold hard photographic evidence. We've mucked about with our cameras and our HTML to give you 16 pairs of matching photos of different spots in Paris – just toggle between the old and the new by sliding the red bar in the middle. So, which do you prefer: colour or sepia?
Its 50 million yearly commuters make the Gare Montparnasse one of the most important stations in the country. It's been funnelling stressed Parisians off to the Atlantic coast for almost two centuries, but hasn't weathered the years gracefully, the stone flooring and tasteful décor of old giving way to metal grills and concrete slabs thanks to a series of uglifying renovations. The new terrace that houses the Jardin Atlantique is an honourable exception.
To look at the luxury fashion boutiques – Chanel, Dior – that line it today, you'd hardly imagine that the Rue Royale is a street steeped in brutal military history. With every turn in the tide of the Revolution, it was renamed by the new pretenders to the government; then in 1871, it was almost razed in the struggles of the Commune. On the wall by the entrance to No. 1, you'll find a copy of a call-up paper for World War One, marking the spot where the original was pasted in 1914.
Built in 1899, the Gaumont Palace was once the cornerstone of the Place de Clichy's nightlife, putting its 6,000-seat auditorium to varied and inventive use (it's witnessed circus shows, football matches and – most bizarrely – naval combats). It subsequently turned into the world's biggest cinema, if its PR is to be believed, while continuing to host events and concerts (notably one given by Frank Zappa on December 15th 1970). It's since been replaced by a hideous shopping centre, though the nearby Pathé Wepler and Cinéma des Cinéastes have assumed its mantle as the film emporia of the area.
Until the mid-19th century, La Chapelle, located between Montmartre and Belleville, was no more than a sleepy satellite village on the outskirts of Paris. It merged with the capital in 1860, and in the last century witnessed a huge influx of immigrants from the Indian subcontinent. The diaspora gave the area its present character: this is still where you come to sample a good curry in Paris. Heading north from the station, you stray into the districts of Marx Dormoy and Pajol, whose gritty industrial backdrops belie the gentrification that they're currently undergoing – soon, Pajol will be home to the largest multimedia centre in the region.
'At around three o'clock in the afternoon, in the month of October of the year 1844, a man of perhaps sixty years of age [walked] down the Boulevard des Italiens, his nose to the ground, his lips paper-white - the appearance of a businessman who's just wrapped up a good deal.' Balzac's description of the boulevard that runs from this metro station, though written down over a century ago, still applies today: this is the part of Paris where men in suits walk shoulder to shoulder with thespians from the nearby theatres – in short, where elegance and sophistication reign supreme. The eponymous Théâtre des Italiens, erected shortly before the Revolution, was situated where the Opéra-Comique stands today.
Nicole Kidman and Ewan McGregor prancing about against a CGI Parisian skyline can't convey this legendary cabaret's reputation for sheer delirious debauchery. The sails of the windmill that adorns the building have been turning since the late 19th century, since which countless music hall entertainers, can-can dancers and bohemian patrons have passed through its entrance. Though today it's all become a somewhat touristic affair, there's no denying the enduring importance of the Moulin Rouge to the city's nightlife.
The 'boul'Mich' – so baptised by anti-clerical students, who took out the 'Saint' and abbreviated the rest – has long been a hotbed of leftist activism. It's on the Place Saint-Michel, depicted above, that several young Résistance revolutionaries were shot down by the Nazis just before liberation. Despite the consumerist invasion, the area retains something of its radical credentials in the form of the cinema Espace Saint-Michel and its provocative programming.
Massively controversial at the time of its construction in the early '70s, the 210-metre Tour Montparnasse nevertheless continues to lord it over the city's skyline. As with London's Centre Point, there's something crushingly drab about its rigid verticality and its exclusive use as office space. It remains the object of much derision, yet perversely also offers arguably the best view in Paris – not least because it has the Eiffel Tower in it.
Once hailed as 'the most beautiful avenue in the world', this over-congested tourist vacuum is now arguably the part of Paris that the city's inhabitants most despise. But for a clutch of car salesmen and a few haggard film critics in the area for press screenings, Parisians simply avoid it like the peste, as do those tourists in the know. There's no doubt about it – the Champs-Elysées is 'the most has-been avenue in the world'.
Though today Rue Oberkampf is better known for its hordes of bars and clubs, this reputation is only a recent development in the street's colourful history. Built over a stretch of the Seine, it long lay dormant as a countryside path before being colonised by traders, artisans and labourers in the 19th century. This ensured that it played a central role in Paris's industrial revolution, and indeed it remained known for its commerce and manufacture before undergoing a facelift and becoming a hotspot for nightlife in the '90s.
A legacy of the big urban planning projects carried out under Baron Haussmann, the square remains one of the main arteries of Paris. Its vast scale, imposing monuments and political associations bring to mind the great squares of Communist cities, and indeed it remains a focal point for popular demonstrations. In 2013 it underwent another, aesthetic kind of revolution, when its two traffic islands were removed to make way for a large pedestrianised area.
One can trace this gently sloping alley's history all the way back to the 1st century AD; today, its stone paving and tightly packed houses preserve something of a medieval ambiance, despite the best efforts of the garish touristic restaurants to ruin it. Yet the proximity of the city's best universities has allowed it to preserve a vibrant student culture at the same time, the best example of which is the delightfully small-scale arthouse Cinema L'Epée de bois.
Until the early 19th century, those looking to reach the Eglise Saint-Pierre de Montmartre upon the hill were obliged to abandon their horse and climb this muddy footpath by foot. This was something by which Napoleon could not abide. Before long, the path was paved, and the Rue Lepic as we know it was born. Today, with its souvenir shops, ample food facilities and newly famous Café des Deux Moulins (star of 'Amelie'), it's become something of a tourist hotspot.