Spend the fourth day immersing yourself in the rich art and culture of Paris. Visit the world-renowned Louvre Museum, which houses thousands of artworks, including the iconic Mona Lisa. Explore the nearby Musée d'Orsay, which is home to an impressive collection of Impressionist and Post-Impressionist masterpieces. After a day of art appreciation, take a leisurely walk along the Seine River and enjoy the beautiful views of the city.