One of the best options to visit historical sites in Paris, is to walk in Paris from one site to another.
Many visitors as expected plan and organize their own map by drawing a personal map or circuit in advance, for the sites they intend to visit during the day, and then they follow their own drawn map to visit places.
We can suggest you to chose the following sites to visit when in Paris :
Marais area (Le Marais), Champs-Elysée Avenue, Lovers Bridge,
Paris center “Chatelet Les Halls”, Sacré-Coeur Around, Saint Luis Islend,
Cygnes(Swans)Island, Latin Quarter(Latin Quartier)
There are some organization groups that provide “walking tours” to visitors who wish to visit Paris by walk and in small interest groups, for example, they provide;
“Fashion Walks” , “Chocolate Walks” , “Old Paris Walks” to mention a few. There are many more organized walking tours, that can be found in the following links;