Most country citizens require a visa to enter Turkey which can be purchased upon arrival at the arrival airports. There are normally two types of tourist visas. A single-entry visa allows you to enter Turkey once. After you leave, no matter how long you’ve stayed in Turkey, you must pay for another visa to enter Turkey again. A multiple-entry visa allows you to enter & leave Turkey multiple times within its period of validity (normally 30, 60 or 90 days) at no additional charge. To get a multiple-entry visa benefitsyou to go to the Greek Islands or any other countries and come back to Turkey with no extra charges. If you are arriving overland from Syria, Greece, Bulgaria or with a cruise, most nationalities will be able obtain a Turkish visa at the border or port customs. Please make sure you have cash (US Dollars or Euros) to pay for your visa when you enter Turkey as no travelers cheques or credit cards are accepted,cash only!
Please visit https://www.mfa.gov.tr/sub.en.mfa?6edc6114-ba75-452d-a7ac-f6d691603318 to get further information about the visa fees.