Paris has two islands in the middle of the Seine river. The building that you see on the right of the photo is the Ile Saint Louis. A place that is magical and also owned mainly by rich Americans, but it is loaded with very traditional French restaurants. Despite being very "touristy" the food is amazing and especially the Ice creams Bertillon!
In front, you have the Ile de la Cite with Notre Dame at the beginning. That night, I had an amazing, fiery sunset and I think it helps create the magical feeling you have when you walk around these places.