Kara Kilise (Turkish “Black Church”) is an unknown church with a cross-and-square plan on the Bithynian Coast in modern Çiftlikköy. It seems to date to the 6th century and might not have originally been a church. It is now located in an apartment complex.
It has been argued that this church marks the location of Pylai, which was important for traffic between Nicaea and the Propontis. Emperors regularly landed at its harbor and one of the beacons was located above the city.