Take a full-day tour of Istanbul and explore it from the perspective of the Byzantine Empire. See ruins of Byzantine churches, Byzantine stone houses, superb mosaics and frescoes at the Church of St. Saviour of Chora, the city’s underground cistern, and more. Traveling by air-conditioned coach, you will drive to the Church of St. Saviour in Chora. The Turkish word "Kariye" is derived from the ancient Greek word "Chora," meaning outside of the city. It is known that there was a chapel outside of the city before the 5th century when the city walls were erected. The first Chora Church was rebuilt by Justinianus and, in the era of Komnenoi, served as the court chapel for important religious ceremonies. Continue to the Fener Orthodox Patriarchate, the Ecumenical Patriarchate of Constantinople and the seat of Orthodox Christianity since Constantine the Great’s declaration of Christianity as the religion of the Roman Empire. Visit Zeyrek Mosque, the former Pantokrator Church. Representing the most typical example of architecture of the Byzantine middle period in Constantinople, it is the second largest religious edifice built by the Byzantines still standing after Hagia Sophia. Hagia Sophia is your next stop. For centuries it was the largest church in the world, and it still boasts the 4th largest dome after St. Paul`s in London, St. Peter`s in Rome, and the Duomo in Florence. Dedicated to the Hagia Sophia, or “Divine Wisdom,” it is one of the greatest examples of Byzantine architecture in survival, and has been called “The 8th Wonder of the World” for its spectacular art and architecture. End your tour at the Basilica Cistern, or Yerebatan Sarayı ("Sunken Palace"), the largest of several hundred ancient cisterns that lie beneath Istanbul. Located 500 feet (150 meters) southwest of the Hagia Sophia, on the historical peninsula of Sarayburnu, the magical atmosphere of the underground palace dates back to the 6th century reign of Emperor Justinian I.