Paris: the city of lights in May... before it became a cesspool. The subway (Metro) was handy, except for the smell of BART. We stayed just below Sacré-Cœur. And just roamed about. Loved the food, hated the prices. We had some travel drama with our friend we let tag along, and we got out just before a strike shut down the airport.
We hunched around Notre-Dame: big, impressive, touristy.
Sainte-Chapelle was far better than Notre-Dame, and a little off the beaten path.
We stayed right beneath Sacre Coeur Basillica: a lot of steps, but a great view of the city.