Sometimes called the Champs-Élysées of Shanghai, this elegant boulevard lined with shady phoenix trees is where the city's elite head for day of shopping. Independent boutiques and turn-of-the-century villas share the strip with sleek malls like the iAPM, which collects a veritable who's-who of high-end designers--from Stella McCartney to Alexander McQueen and Balmain to Prada--under one gleaming roof.