Church of the Holy Apostles built
501 CE.
Shown on the map at 41.020°, 28.950°.
The Church of the Holy Apostles (Greek: Ἅγιοι Ἀπόστολοι, Agioi Apostoloi; Turkish: Havariyyun Kilisesi), also known as the Imperial Polyandrion (imperial cemetery), was a Byzantine Eastern Orthodox church in Constantinople, capital of the Eastern Roman Empire. The first structure dated to the 4th century, though future emperors would add to and improve upon it. It was second in size and importance only to the Hagia Sophia among the great churches of the capital. When Constantinople fell to the Ottomans in 1453, the Holy Apostles briefly became the seat of the Ecumenical Patriarch of the Eastern Orthodox Church. Three years later, the dilapidated edifice was abandoned, and the patriarchate moved to the Theotokos Pammakaristos Church. In 1461, the remains of the Church of the Holy Apostles were demolished by the Ottomans to make way for the Fatih Mosque.
Text from the Wikipedia article Church of the Holy Apostles, licensed CC BY-SA 4.0.