But the Seine isn't Paris' only river. There's another secret stream flowing deep under the streets -- if you know where to look.
Centuries ago the Bièvre river wound its way through the city, becoming a polluted dumping ground for businesses, eventually sealed-up in 1912. Today, walking tours follow plaques marking the hidden river route.
You don't need to go to the Louvre to see amazing art
You could line up for three hours to get into the world's most visited museum. Or you could wander the city at leisure, taking in some of the most skillful street art in Europe.
If you want to see more than just the usual Banksys or pixelated mosaic "space invaders," then there are plenty of walking or cycling tours to give you an in-depth tour of Paris' more obscure murals.