Adana-Sakirpasa Airport (ADA/LTAF)
Ankara - Esenboga Airport (ESB/LTAC)
Antalya Airport (AYT/LTAI)
Dalaman Airport (DLM/LTBS)
Istanbul - Atatürk Airport (IST/LTBA)
Istanbul - Sabiha Gökçen International Airport (SAW/LTFJ)
Izmir - Adnan Menderes Airport (ADB/LTBJ)
Out of the major Turkish Airports above, I'd guess Antalya, Dalaman or Izmir if it definitely isn't Istanbual or Ankara.