If you have an extra day, take a day trip to the Palace of Versailles. Visit the Palace, the breathtaking gardens, and the Hall of Mirrors. If you don't have enough time, skip the Latin Quarter and spend more time at the Louvre or Eiffel Tower. Keep in mind that many museums and attractions in Paris are closed on Mondays, so plan accordingly. Lastly, consider purchasing a Paris Museum Pass, which offers unlimited access to over 50 museums and attractions in the city, as well as skip-the-line priority access.