Definitely recommended to do an "oldcitytour" Must see the highlights of the city with a customisable privet tour guide. Such as, *One of the world's great architectural masterpieces at the Hagia Sophia *Wander the stores of the Grand Bazaar *Blue Mosque and more. Check back for the tour guide details....
Visit legendary landmark: Galata Tower recommend in the evening hours night view is amazing!Recommend to get off at Taksim Square which is like (time square) It’ll be a 10-15mn walk on the famous Istiklal Street to the Galata Tower. You’ll witness the crowd that locals live in everyday. Shops, street music, life is on that street.
The Egyptian Bazaar (Mısır Çarşısı), otherwise known as the Spice Bazaar, is the place to be to lay in a fresh supply of spices, nuts, honeycomb, Turkish delight, dried figs, caviar and mature hard Turkish cheese.The Spice Bazaar was built in 1664. The main entrance to the Spice Bazaar is via a high brick arch on the pigeon infested plaza next to the New Mosque in Eminönü.
If you are staying longer in Istanbul and you'd like to escape the hectic city for a day. Try taking a fast ferry to Islands.