When you've finished drinking in the wonders of Notre-Dame, cross the Seine via the Pont au Double and wander west along the quai de Montebello. This is where you'll find the bouquinistes, or booksellers, whose wares run the gamut from priceless antiquarian rarities to dog-eared copies of yesterday's bestsellers. They also sell art prints of Parisian views, many of them anodyne rubbish, but if you take the time to browse you may well find an appealing souvenir.
The Southwest regions of the Gers, the Lot-et-Garonne and the Tarn-et-Garonne descend upon Paris each September for a culinary and tourism festival that draws upwards of 200,000 visitors annually. 42 small producers and artisans will set up stands in an open-air market along the Quai de Montebello and the Quai de Tournelle, across from Notre Dame. Concerts, games and tastings are also offered over the course of the 3 day festival (September 13-15), making it a terrific opportunity to discover the terroir of the Southwest and engage firsthand with locals who are tremendously proud (and rightfully so) of their region.