The Eiffel Tower, the Louvre, Musée d'Orsay, Notre-Dame de Paris Cathedral, Champs-Elysees Avenue, Arc de Triomphe, Center Pompidou, Sacre Coeur Basilica, Catacombs of Paris, Palace of Versailles, Sainte-Chapelle Church and Latin Quarter. If you're looking for something unique and off the beaten path during your trip to Paris, I highly recommend Montparnasse Tower Observation Deck. You can get an unparalleled view of the city from its 209-meter observation deck.  Another great spot is the Luxembourg Gardens in the 6th arrondissement for its sprawling gardens filled with trees, sculptures, and fountains.  Last but not least, I suggest stepping back in time by visiting Place des Vosges, Europe's oldest square in the Marais district.