Istanbul is a city where the past collides with the present. The Raffles Istanbul, connected to the high-end retail hub of the Zorlu Center, beautifully exemplifies the contrasts. To get a taste of the Ottoman empire, book a room at the Four Seasons Bosporus, set in the restored Atik Pasha Palace. Modernists should stay at the Marti Hotel, located in the heart of the city's business district. For the cool kids, there's the House Hotel, which oozes urban Bauhaus style.