There are so many that I could almost fill this page. This site has the top ten but there are many many more. Google your question and you'll see pictures of all the things to see in Paris. I never got to see even half of those when I was there.
10 Top Tourist Attractions in Paris – Touropia Travel Experts
www.touropia.com/tourist-attractions-in-paris
about-france.com/paris-tourist-attractions.htm
Notre Dame, The Eiffel Tower, The Arc de Triomphe de l'Etoile, The Louvre. They are all great to see and are very crowded. I suggest you take one of the boat tours down the Seine. I learned more from that and got my bearings that way. And quite frankly, the best thing you can do is just get on the metro to get around and walk the different districts.
According to me, The Eiffel tower, the Paris Opera house, the Louvre art museum, Notre Dame cathedral are a few. When I went a few years ago we went to the hard rock cafe. It was neat and if you're taking kids that might be something they would be interested in too.
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