Transportation options: 1- Taxi ( pricy )

First of all, when you arrive in Istanbul, there is a big chance you get stuck in traffic, so it is important to get to metro lines as soon as possible. Especially around rush hours ( 07:30 – 09:30 ) ( 16:30 – 19:30 ) Easiest way to get to metro lines:

1 – By IETT busses: Number H-8 It will take you to Hacıosman which is the first destination of Hacıosman – Yenikapı metro line.

2- By Havaist busses: Number IST – 5 ( Ticket price : 18 TL ) By using IST-5 bus you can take off at 3 different stops.

To be able to use public transport you need to have an Istanbul card. Which you can buy at the airport. Don’t forget to put enough money in it, because it’s the only way to pay for the buses from IST airport.

If your stay is longer than a day, and you will use it multiple times ( like 20 times maybe ), buying a card for each person is better. If you’re going to use it couple times, you may get one card only and use it for more than one person. The card can be used for metro, marmaray, metrobus, ferries etc. It is an anonymous card and price is : 6TL Once you reach to Hacıosman or 4.Levent Metro station ( different stops on the same line) you can get to Taksim or Yenikapı directly. See the image below.

Once you reach to Yenikapı station, you’ll continue to Marmaray Metro line which connects european and asian side ( going through a tunnel under the sea ). By using marmaray you can get to Uskudar directly, or Kadıköy at Söğütlüçeşme station. See the image below:

If you have a limited time in Istanbul, I’d suggest you to drop off your luggages at the airport. There are luggage storage ares you can securely lock your luggages.

I translated the information below from this PDF file provided, couldn’t find an English version. Link to PDF file