I think Le Corbusier must be the most famous architect in France. I was majorly hankering for a architectural tour, after visiting Alvar Aalto's studio and home in Helsinki last summer. I did a bit of Internet research, and Le Corbusier was the only architect who came up! In case any of you don't already know, Le Corbu is the most pre-eminent French modern architects.
In Paris, there are a few main architectural sites, designed by Le Corbusier. You can visit his house and studio, but unfortunately I procrastinated too much for that. Because of the timing, I was able to see Le Pavillion Suisse, La Maison du Brésil, and, La Cité de Refuge.
Le Pavillion Suisse and La Maison du Brésil are pretty close to each other. They are both part of Cité Universitaire, a college in Paris that was created to attract students from all over the globe. They have a lot of other interesting buildings that are used for student housing, but these are the only two from Le Corbusier. I would suggest you plan on spending a morning there, and wandering a little, if you have the time.
Le Pavillion Suisse is open from 10 to 12 am, and 2 pm to 5 pm. What I didn't realize, before I visited the South of France, is that many take an extended lunch break.
Anyway, I think I arrived around 11 am, and needed no more than 30 minutes to see everything Le Pavillion Suisse had to offer.
So to backtrack a little, you need to take the metro or tram to Cité Universitaire. You enter, and there should be pretty clear signs to each building. Back when it was created, only Brazilian students lived in the Brazilian building, but now anyone can live anywhere.
It is 2 euros to enter La Pavillion Suisse and you have access across the ground floor, and on the first floor in the hall, and in an orginal student dorm room. It's definitely the least expensive museum you can visit in Paris, and well worth it.