A good idea is to take the métro (line 1) to the Arche. There is a big mall with a cinema and this means that there will always be tons of people to photograph. The area is full of street photo possibilities. The arche itself makes for an amazing backdrop with geometry (plenty of lines) and reflections.
But there's plenty more to see if you wander away from the arche. Don't be afraid to go off to the side routes. Modern sculptures seem to appear pretty much everywhere. You've got the Japan Bridge, the Moretti column (among many other columns), the Alexander Calder red sculpture.
A few of my favorites taken in front of the Moretti Chimney
Looking for more photos of Paris ? Check out these other categories.
All photos taken by Sylvain Duchêne