I bought some cute postcards with old pictures from Paris. This one was taken near the river la Seine in 1951.
In 1991, the Seine River, its banks and bridges were declared UNESCO’s World Heritage Site.
The following information comes from the UNESCO’s website:
From the Louvre to the Eiffel Tower, from the Place de la Concorde to the Grand and Petit Palais, the evolution of Paris and its history can be seen from the River Seine. The Cathedral of Notre-Dame and the Sainte Chapelle are architectural masterpieces while Haussmann’s wide squares and boulevards influenced late 19th- and 20th-century town planning the world over.
Paris is a river town. Ever since the first human settlements, from the prehistoric days and the village of the Parisii tribes, the Seine has played both a defensive and an economic role. The present historic city, which developed between the 16th (and particularly the 17th) centuries and the 20th century, translates the evolution of the relationship between the river and the people: defence, trade, promenades, etc.
It can be seen how the site and the river were gradually brought under control with the articulation of the two islets, Île de la Cité and Île Saint-Louis with the bank, the creation of north-south thoroughfares, installations along the river course, construction of quays, and the channelling of the river.
The ensemble must be regarded as a geographical and historic entity. Today it constitutes a remarkable example of urban riverside architecture, where the strata of history are harmoniously superposed.
Let’s not forget les bouquinistes, selling old books and souvenirs along the river:
Until the 19th century, Paris was France’s busiest port, and the city council was actually founded by river merchants.
For most of its history, the city drew its water from the Seine, which lost its purity about 1,000 years ago.
At the end of January 1910, the river rose 8.62 metres and burst its banks, partially submerging the city for 35 days.
The sewers and the métro were flooded, countless cellars were turned into swimming pools, and many ground-floor apartments had to be evacuated. The Eiffel Tower, built on a bed of sand, shifted 2 centimetres off the vertical.
By 1970 the river was so polluted that it was pronounced “nearly dead”. Since then, the situation has slowly improved. Today, hundreds of employees work around the clock to keep the river tidy, they control its flow and purify its water. This is not done merely to please environmentalists or the tourism board. The fact is eighty percent of Paris’s drinking water comes from the Seine.
The Seine is getting cleaner, and apparently there are now 29 species of fish swimming past the Louvre and under the Pont Neuf. Even so, bathing in the river has been forbidden since 1923.
Source: http://whc.unesco.org/en/list/600 and Stephen Clarke, Paris Revealed. The Secret Life of a City.