Cities you can travel by train from Istanbul
Haydarpasa in Istanbul used to be the departure point of many long distance trains to Anatolia. However with HST connections to Ankara, Konya and Eskisehir, it’s possible to use most of the main line trains with one interchange.
Some of the HSTs and Ankara Express call at two stations in European side of Istanbul, Halkali and Bakirkoy. The regional trains in westward depart from Halkali.
Trains call at 3 stations in Asian side of Istanbul: Sogutlucesme, Bostanci and Pendik. From these stations, you can travel to Ankara and Konya-Karaman via Izmit-Bilecik-Eskisehir. From the last station of Marmaray in Asian side, Gebze, Ada Express is departing to Adapazari.
Trains departing from Sogutlucesme (Asian side)
Trains departing from Halkali (European side)
There are three cities that you can travel to and use a connected train: Ankara, Eskisehir and Konya.