The Rue des Martyrs climbs north from the 9th toward the foot of Montmartre, and along the way it is one of the best food streets in Paris: an almost unbroken run of bakeries, pâtissiers, cheesemongers, fishmongers, chocolate shops, wine merchants, and small bistros. It is a working market street rather than a tourist set-piece, busy with locals doing their daily shopping, and the quality is consistently high.
The lower, pedestrian-friendly stretch in South Pigalle is the densest and most rewarding. Come hungry, graze as you go, or assemble the makings of a picnic. Mornings and Saturdays are busiest; like most Paris food streets, much of it closes on Monday.