The Braderie de Lille is one of Europe's great annual events and completely transforms the city for the first weekend of September. The entire historic centre — every street, square, and pavement — becomes a continuous flea market stretching for kilometres in every direction. Antique dealers from across Europe set up alongside ordinary households selling old clothes, broken furniture, and mysterious electronic equipment. The mixture is democratic and genuinely excellent for treasure hunting, with genuine finds available if you arrive Friday evening before the professionals have picked everything over.
The city's restaurants compete to pile the highest mountain of moules-frites shells outside their doors during the Braderie — a tradition that produces spectacular mounds of shells by Sunday afternoon and fills the air with the smell of steamed mussels and beer. Eating moules-frites during the Braderie is practically obligatory. Accommodation in Lille is fully booked months in advance for this weekend — book early or stay in Roubaix, Tourcoing, or Belgium.