Many of the large cities have daily connections to the traffic hubs Ankara and Istanbul. Turkish Airlines has flights among major world and Turkish cities.
Travelling by plane:
Turkish Airlines has flights among major cities which are convenient for longer distances, and relatively inexpensive. Onur Air, Atlasjet, Pegasus Airlines, and Sun Express have growing route systems and even lower fares.
Travelling by bus:
If you whish to travel by bus, thousands of modern, luxurious buses roar between Turkish cities and towns, and countries, every day.
Travelling by car:
If you are an experienced driver that want's freedom of movement, consider driving with your own car to Turkey or renting a car in Turkey.
Travelling by train:
The Orient Express is gone, but train travel in Turkey is still useful, especially trains between Ankara and Istanbul. Expresses, Super Expresses and sleeping car trains are somewhat slower than the bus but offer more seating-room and comfort for less money.
Sea of Marmara ferry services run between Istanbul on the north shore and Yalova and Bandirma on the south shore, and across the Dardanelles.