A soak in a Turkish bath or "hamam" is a must-do. Each of the city's eight districts includes at least one historical hamam where you can indulge in a massage or simply relax in the sauna. After your soak, try a few puffs from a traditional waterpipe known as a nargile or hooka. Many locals consider a conversation around the hooka one of life's great pleasures.
Take a step back in time with a four mile walk along the Theodosian Walls, an impressive series of defensive stone walls that have enclosed and protected Istanbul since their construction in the fifth century. View Istanbul from the sea with a ferry ride along the Bosphorus, then disembark in the village of Anadolu Kavagi to explore Yoros Castle, dramatic citadel ruins overlooking the Black Sea.
In the city's humming markets, treat yourself to Turkish Tea and Turkish Delight, a pretty confection flavored with rosewater, lemon and pistachio. The markets are also a great place to pick up Turkish rugs or jewelry encrusted with chalcedony, a semi-precious stone named for the nearby town of Chalcedon.
When your appetite calls, indulge in local street food favorites like döner kebabs, balik-ekmek (fish sandwiches), roasted chestnuts or dondurma, a local ice cream flavored with orchid root extract.