Unfortunately, reaching Sultanahmet by public transport is difficult and will involve multiple methods of transport. There is, of course, the option of taking a Sabiha Gokcen airport taxi which can be much more convenient, but due to the location of the airport quite a way out of the city, much more expensive. The ride can be about 90 minutes and cost around 28€ (140TL). The Havabus from the airport will not go to Sultanahmet but will deliver you to two locations – Taksim Square 2.40€ (12TL) or Kadikoy 1.80€ (9TL), therefore you will need an alternative mode of transport for the onward journey from both locations, either ferry and tram or metro and tram. Welcome Pickups offers meet and greet services and a friendly introduction to Istanbul at the same price as a regular taxi. Click here to see the cost.