The Musee d’Orsay is home to the best impressionism collection in the world. Monet, Manet, Van Gogh, Renoir, Degas, Toulouse-Lautrec are all here in a beautiful setting. Check for sure, but it has been closed on Mondays.
To get a sense of The Louvre, you’d need several days…probably weeks. For that reason, plan in advance. I’ll cover more specifics about The Louvre later. Again, check to be sure, but it has been closed on Tuesdays.
The Musee Rodin is fantastic and the outdoor sculpture garden is even better.
More museums later…