When i was on a cruise it called into Istanbul . The cruise rep tryed to sell me a tour of IST but it included a river boat lunch and 2 hours in the grand bazar , 2 hours i'd need 2 days . the price was £30 . she said it was.nt safe to go alone into the city ? also said 9 million people live there LOL ??? Early next day i got a taxi i asked driver to take me to the sites { except river boat } We went all over the place blue mosque big church ottaman houses . Shopping . football pitch etc Price £20 and i bought his lunch . So if you know what you want to see consider taxi.s I enjoyed it more than a guided tour I looked at what i wanted to not what they wanted me too ....Diane