No trip to Paris would be complete without a stop at Notre Dame, and rightly so. In my experience, some of the great monuments and buildings in Europe have been so built up and seen so many times that by the time you actually see them, it can be a bit of a letdown. But that is certainly not the case with Notre Dame.
It leaps out of the surrounding scenery and immediately pulls you in. I do remember thinking it looked smaller than I had imagined, but that was just in driving up to it. Once you are standing in front of the cathedral, staring up in awe at the extremely intricate carvings above the entrance, all thoughts of it being small evaporate.
I remember that the weather was bad the day I stood before the cathedral, built between the 12th and 14th centuries, and even without the light that would have made it so stunning, I still found myself in awe. I think the real majesty of Notre Dame is in its stained glass. Some of the windows inside the cathedral were unlike anything I've seen before or since. I remember pulling out my best slide film to put in my camera and sending out a small wish I'd be able to capture something of them with out the benefit of good lighting. All indoor shots of cathedrals are inevitable letdowns, but to this day, the best ones I have came from Notre Dame. I recommend that you double-check on opening times, as they are a little tricky in being arranged around the mass schedule, as it is still a cathedral.
Guided tours are available, though I recommend a quiet wander yourself around the inside. Even if you're not snapping photos (which you will certainly want to), it's a peaceful and stunning place that leaves a quiet impression on you. If you can go in the off-season, I would recommend it---I need to revisit Paris if for no other reason than to sit alone in the sanctuary of Notre Dame without a tour group calling out the next itinerary. If you're in Paris, make time for this. You won't regret it.