Photo: Ezzeldin.Elbaksawy, CC BY-SA 4.0 via Wikimedia Commons
The original mosque was built between 1463-1470 by the Greek architect Atik Sinan, by order of Sultan Mehmet II the Conqueror, on the site of the former Church of the Holy Apostles, which had served as Byzantine Imperial burial place for a thousand years. The grand complex with eight medreses, a library, hospital, hospice, caravanserai, market, hamam, primary school and public soup kitchen was smashed again and again by earthquakes, and the present building is from 1771 to a different design. The interior is lavish, and outside is the ornate tomb of Mehmet II and his wife Gülbahar Hatun.
The Fatih Mosque is an Ottoman mosque off Fevzi Paşa Caddesi in the Fatih district of Istanbul, Turkey. The original mosque was constructed between 1463 and 1470 on the site of the Church of the Holy Apostles. Seriously damaged in the 1766 earthquake, it was rebuilt in 1771 to a different design. It is named after the Ottoman sultan Mehmed the Conqueror, known in Turkish as Fatih Sultan Mehmed, who conquered Constantinople in 1453.
© OpenStreetMap contributors
This is a triple structure: the church of the Monastery of Pantokrator built 1118, then a public church circa 1136 plus a chapel that served as a royal mausoleum. It became a mosque and medresse in Ottoman times, but without massive alteration so it's a prime example of middle-Byzantine architecture. It's nowadays again a mosque, photogenic by day or dusk but the area should be avoided at night.
Turkish: Özel Fener Rum Lisesi, Greek: Μεγάλη του Γένους Σχολή
This is the red-brick castle seen south of St George. Built 1881/83, it teaches the standard Turkish curriculum plus Greek language and culture, and the tower houses an observatory. No visits.
Turkish: Aya Yorgi, Greek: Agíou Geōrgíou
This is modest from the outside, as the Ottomans would not permit non-Muslim religious buildings to rival the mosques. The interior is lavish but its chief importance is as the senior Eastern Orthodox church. Their Patriarchate has been housed here since 1586 when they were ejected from Agia Sophia.
Pammakaristos Church
The Church of Theotokos Pammakaristos ("All-Blessed Mother of God") was built between the 11th and 12th centuries. The parekklesion or side-chapel was added maybe 1300, with rich mosaics. The main building became a mosque in 1591, named for Sultan Murad III's conquest (fetih, hence Fethiye) of Georgia and Azerbaijan: the interior was opened up, but the chapel was undisturbed and in modern times became a museum. In 2020 the entire building was proclaimed a mosque, and every scrap of Byzantine artistry was covered up, so now there's nothing worth seeing.
On top of a hill overlooking the Golden Horn, this is a magnificent mosque built by Sinan in the 1550s. It was centrepiece of a large külliye, a religious complex which included madrasas, a public kitchen and a hospital.. The small cemetery east has the mausoleums of Suleiman the Magnificent and of his wife Hurrem Sultan or Roxelana.