N.A. (before July 2018)
Mobile phone store. http://maps.google.com/?q=39.10281,26.55629
Sells SIM cards. Cosmote has good coverage but the service there is not welcoming or supportive.
Be sure that you prevent roaming! It can drain your account! Ask them to block Internet after the packages is used otherwise it switches to a far more expensive service. E.g. when you use 500MB it uses a price per MB scheme
Make sure that the do not bull shit you.