The Canal Saint-Martin was built to solve a public health crisis. In 1802 Paris had no piped water - households drew from the Seine (then a working sewer), shallow wells (contaminated), or paid water-carriers who came up the hill from the river. A cholera outbreak that year killed thousands. Napoleon - then First Consul, not yet Emperor - issued a decree on 29 Floréal Year X (19 May 1802) ordering the construction of a fresh-water canal from the Ourcq river 100 km east, into Paris, via three downhill canals: the Canal de l'Ourcq, the Canal Saint-Denis and the Canal Saint-Martin. The water would be drinkable; the canals would also carry coal, stone and grain barges directly into the city. The plan was financed by a wine tax. Construction took 23 years; the canal opened in 1825.
A working canal until the 1960s
For 140 years the Canal Saint-Martin was working infrastructure. Barges moved grain from the Brie, stone from Beauvais, coal from the north and Picardie. The basins at La Villette were Paris's main wholesale produce yards (the Marché aux Bestiaux - cattle market - was there till 1974). The 10th arrondissement, which grew up around the canal, was a working-class neighbourhood of railway workers (Gare de l'Est and Gare du Nord are both a 10-minute walk), barge-handlers, tannery workers, and the staff of the great Hôpital Saint-Louis (the 1607 plague hospital, still operating). The canal froze in winter; children skated on it. Boris Vian wrote a song about it (Le Déserteur, 1954). Marcel Carné set Hôtel du Nord here in 1938 and made it shorthand for the Paris of working people.
By the 1960s the canal had been overtaken by trucks and trains. There was a serious proposal in 1971 to cover the entire 4.6 km with a motorway - an idea so close to being executed that demolition plans were drawn up. A grassroots resistance campaign, supported by Carné's film and a public petition, killed the project in 1974. The canal was instead listed as a historic monument in 1993 and the locks and bridges have been progressively restored.
Amélie and the second life
Jean-Pierre Jeunet's 2001 film Amélie - filmed in part on the Quai de Valmy - introduced the canal to international audiences. The skipping-stones scene was filmed on the Quai de Valmy by the Pont Tournant de la Rue Dieu (the swing-bridge); Audrey Tautou stands on the lower quai and skips the stones across the water. The Hôtel du Nord scene was filmed on the bank. Other scenes used the Café des Deux Moulins in Pigalle (not the canal, despite some confusion).
Through the 2010s the canal became one of the symbols of "bobo Paris" - the bourgeois-bohémien (bobo) caricature of young professionals with kids who'd rather live in the 10th than the 16th. Quai de Valmy filled up with vintage shops, Le Comptoir Général (a curiosity-shop bar in a former tropical-fish dealer's), Holybelly for brunch, Du Pain et des Idées for bread, Liberté for pastry. The Sunday car-free quais became a city-wide rendez-vous. The Hôtel du Nord building, saved from demolition in 1989, reopened as a brasserie in 2005 and now hosts a permanent Carné-Arletty exhibition in a back room.
What's actually here
The canal walk has nine working locks (Écluses du Temple, Bonne Nouvelle, Récollets x2, Bichat, Restigouche, La Villette - the names matter to barge crews more than to walkers), eight iron pedestrian footbridges, two swing-bridges (the Pont Tournant de Rue Dieu and the Pont Tournant des Récollets), and seven arched stone road-bridges. The water is 25 metres higher at the north end than the south end - hence the lock chain. The 2 km from République to Bastille runs underground under Boulevard Richard-Lenoir, vaulted by Baron Haussmann in 1860 to accommodate the new boulevard above.
The neighbourhood is still working-class enough to feel lived-in, but the gentrification is real - hotel rates have doubled since 2015, the small businesses around Rue de Lancry have turned over. The Hôpital Saint-Louis (a 1607 plague hospital that became a teaching hospital, still operating) has free courtyard gardens open to the public most days; they are some of the quietest spaces near the canal. Place Sainte-Marthe, two blocks east of the canal, is the village-within-the-neighbourhood: a tiny cobbled square with painted houses and three of the city's best cheap restaurants (Chez Marie-Louise, Brasserie La Marine). The Atelier des Lumières (digital art, 38 Rue Saint-Maur) is a 15-minute walk south-east. The Northern Marais is a 15-minute walk south. The canal is the city's connecting tissue here.