Public pay phones (in Turkish: Ankesörlü Telefon) are the cheapest way to talk in Turkey. You can find pay phones in almost all the public areas. You can use phone cards or credit cards to make phone calls. Phone cards can be found at the post offices, newsstands and other street kiosks.
Privately owned pay phones (in Turkish: Kontürlü Telefon) can be found at the street kiosks in touristic areas and mostly in the neighborhood grocery stores. There is a meter attached to these phones which calculate the unit you use. You pay in cash for the call units you used. Because there is no standard unit rate be sure to ask how much is per unit. Try not to use these phones for international calls unless it is an emergency.
Calling from your hotel is probably the most expensive way of calling in Turkey. If you have to use the phones in the hotel, make a call, give the hotel phone number and your room number and tell them to call you back. This will definitely cheaper than hotel calling rates.