The train station at Hyderpasa connects Istanbul with the remaining part of Turkey and the rest of Asia.
There is a train station is Sirkeci, near the harbor, but there is no train connection between the European Istanbul with the Asian Istanbul.
However, most hotel and tourism objects in Istanbul rests on the European side. Hence, if you want to take the train from Istanbul to other Turkish cities (Konya, Cappadocia, etc) you have no option but to cross the Bosphorus strait with a ferry to Hydarpasa station. The crossing takes 15 minutes.
If you are travelling with tram, stop at Elmeneu which is one stop after Sirkeci. The tram door is on the right (Tram price: 2 TYL).
From Elmeneu, you have to pass several docks until you find the dock with the ship that will take you to Hyderpasa. Make sure you ask if the ferry goes to Hyderpasa. At the left hand side of the entrance there is a ticket machine, the coin costs 2 Turkish Liras. Wait for the ferry to arrive. From my experience Hyderpasa is the first stop after Elmenou but be sure to ask someone in case the itineraries change.
Below is the picture of the commuters on the ferry. They work in Europe but lives in Asia and has to cross the strait before cacthing a tram at Hyderpasa. But the trip is convinient, so, no worries :)
One more tip: The station restaurant at Hydarpasa is quite expensive. If you are budget-travelling I'd advice you to eat somewhere else. But, the back side of the restaurant is very beautiful. You can watch the busy port from the back.
Do leave me a message at the comment section if you have any question.
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