How does the Seine divide historic Paris?

The Seine defines the three main parts of historic Paris, serving as a central axis for the city's development.1

• Île de la Cité: Located at the center of the river, this island serves as the historic seat of both religious and temporal authority and is considered the nucleus of the ancient city.1
• Left Bank (Rive Gauche): Traditionally, this side of the river has been the seat of the city's intellectual life.1
• Right Bank (Rive Droite): Historically, this area has contained the heart of the city's economic life.1

While these traditional roles have become more blurred in recent decades, the designations remain a fundamental way of understanding the geography of historic Paris. Parisians determine these banks by facing downstream, ensuring the names remain constant despite the river's winding path through the city.12