The cost will be an amazing 4 Turkish lire per person one way from the airport to Galata Bridge. At the airpport, buy 2 tokens (or double for return) per person at the Metro station in the airport. A token is a round plastic disc costing 2TL each. you can also buy then like parking ticket from a booth at each station. Take the train (metro) till station Zeytinburnu. Remember they ‘drive» on the right side here! This will cost you one token per person and it is the 6th stop and all stations are clearly announced. At Zeytinburnu,using your second token, change to tramway line Zeytinburnu- end stop Kabatas, really easy and clearly indicated. Now sit back and enjoy the journey till about the 19th stop which is Eminonu, just before the Galata bridge, a busy area where Bosporus ferries take off. From here you walk a few minutes to the Galata bridge. First walk to the bridge. There is a nice area just past the bridge to sit and watch the goings on and it is here where you see the two rocking boats where they fry the fish sandwiches, you will see it clearly. In the same area, walk inland and you will find the Spice bazaar. I also enjoyed a quick visit to the small Rustem Pasa Mosque (Camii) hidden in this bazaar area, its renowned for its lovely tiles. Also lovely, is to walk over the bridge to the Galata Tower. If you have time, also walk istiklal Street on Galata tower side, it so busy its like the fan walk in Cape Town after a world cup match! Or else justfollow the tram line back to the «old city — Sultanahmet area — the way you came by tram, tracing back your «footsteps» so to speak. Lots of restaurants and shops everywhere especially between Sirkeci and Gulhame stops. Eat supper somewhere there, then hop back on the tram to Zeytinburnu, there get back to Metro line for «havalimani» (airport) leading you straight to check in for international airport, easy as pie. Just one word of caution — at Yusafpasa station they announce in english that that iis the changeover for the airport. Whilst that is correct, it means that you have to walk quite a bit to make the connection. JUST STAY ON THE TRAM till Zeytinburnu, its easier and quicker. if you miss a station, just get off the tram, cross the lines and travel back to the missed station, seems exceptable practise and then you dont have to buy new token. Just search for the Istanbul tram and metro map on internet and most of the above will make sense.