Both the Ortaköy Princess hotel and the Feriye Convention Hall are located approximately 30 minutes drive from Istanbul’s airport. Unfortunately, there is no direct public transportation to the hotels. Therefore, the easiest and fastest way to arrive at the hotel is by taxi. The rate for a taxi ride from the airport to the hotel is around 40 Turkish New Liras (=22.3€).
For your information:
The address of the Princess hotel is 36 Dereboyu Cad, Ortaköy.
The address of the Radisson hotel is 46 Ciragan Cad, Ortaköy.