Concierge.com's insider take:

The very heart of Istanbul, this mile-long pedestrian street that runs from Tünel to Taksim Square is regularly mobbed by residents who come for the shops, cafés, and restaurants. The Tünel end is marginally quieter, with a small street, Galip Dede Caddesi, leading down to the Galata Tower. From Tünel, you can explore the backstreets of Asmalımescit, a bohemian neighborhood of cafés and bars that's especially animated on weekend nights. A relaxing way to see the İstiklal Caddesi is to take the historic tram that trundles sporadically from Tünel to Taksim Square and back again—though in doing so, you'll only catch a glimpse of all the vibrant streets and alleys that shoot off the main drag. If you can tolerate the crowds, this district is best wandered through on foot.—Vanessa Able