Plaça de la Seu
Every Thursday, the Plaça de la Seu at the base of the massive 15th-century cathedral—the most famous edifice in Barcelona (not counting the Gaudís)—hosts an outdoor flea market. The offerings are surprisingly upscale and usually include seductive antique jewelry, lovely old dolls, and printed advertising items. Though the market itself is not enormous and can be covered in one leisurely morning, the quality of the goods makes up for the small number of dealers.
Hours: Thursdays only.