To Zola, it was a bustling, centuries-old food market that provisioned the whole city. Today’s les Halles, a 1970s underground mall, is more or less universally loathed. That’s set to change however, with a sweeping architectural revamp due to begin in 2008. It will also transform the gardens, a magnet for unsavoury types. At their western edge is the circular Bourse, Paris’ stock exchange. Nearby, the imposing Gothic church of St-Eustache (p.161) wasn’t completed until 1637, which explains its renaissance interior. Among its attributes is an exuberant modern relief of the Les Halles traders. Foodies should make a beeline for lively rue Montorgeuil, where several fine old purveyors include Stohrer, in the patisserie business since 1730. Here, Les Halles rubs shoulders with Sentier, home to the rag trade (you may just catch the growl of sewing machines.) On rue Étienne-Marcel, the Tour Jean-Sans-Peur (p.167) is a wonderful survivor from the Hundred Years War. It was built for the Duke of Burgundy, who later lost power as bloodily as he gained it.