If you are a Europe traveler and you are familiar with the fabulous Goth churches, you might not be so impressed by Notre Dame de Paris; especially if you see all the construction / advertising business going on in front of it.
However, Notre Dame de Paris remains a fine example of French Gothic architecture. Naturalistic statues adorning its walls as well as rose stained glass windows are typical of its era.
The heart of Parisian Catholic church has free entrance and it is estimated that 14 million people visit it every year.
A lot of people go to the park in square Jean XXIII to get a good photo of Notre Dame. You could also climb the tower via 422 spiral steps if you feel like it, for those spectacular views.