A nice location in Istanbul is Otakoy-stroll the local neighborhood and enjoy a mint tea and sheesha on the waterfront. Local fisherman bring in their catch and even toss the cats hanging around a few treats. In the evening, young couples walking hand in had come out to enjoy the cooler temperatures,often going to the local vendors selling baked potatoes overflowing with toppings.
I typically like to run or ride to find my way in new places. The heart of Istanbul was one of the trickier spots to do this BUT, with a little dedication and planning you, too, can enjoy running in this fascinating and beautiful city! Running is best on the outskirts of town (I enjoyed sleepier Ortakoy), and outside of the city center where the traffic is less imposing, and it seems to be an environment more welcoming runners (especially we avid women!) Nike has published a great guide for running in Istanbul that I used as a primer for my own trainer adventures (which occasionally required a taxi to my run start.)