For the week we spent in Paris, we rented an apartment in the 2nd arrondissement. It is a terrific location, just a short walk to the Royal Palace, the Louvre, close to two subway stations and in an area with lots of restaurants and shops. In addition, it is about 4 blocks from Palais Garnier (pics), one of the most famous opera houses in the world.
Our host for the apartment suggested either taking the tour of Palais Garnier or, better yet, checking out ticket availability for performances while we were staying there. We did just that and found that we could get tickets.