The city's greatest tourist magnet reads like a to-do checklist: Navy Pier, the John Hancock Building, art museums and galleries, lakefront activities, and countless shops where you could spend a few dollars or thousands. The Magnificent Mile, a stretch of Michigan Avenue between the Chicago River and Oak Street, owes its name to the swanky shops that line both sides of the street. Shoppers cram the sidewalks in summer and keep the street bustling even in winter, when the trees are twined with thousands of white fairy lights and the buildings are lighted with colored flood lights.