Start your tour with a hotel pickup, and then travel by luxury coach along the shoreline of the Golden Horn -- the Bosphorus Strait’s natural bay that was an important international shipping harbor during the Byzantine era.
Stop in the Greek neighborhood of Fener at the Ecumencial Orthodox Patriarchate  an intriguing church compound where the ceremonial head of the Greek Orthodox Church is based. Visit the Church of St George (the site’s main church) and see its Byzantine patriarchal throne, dripping with opulent ornamentation.
Continue to the historical neighborhood of Ayvansaray, known in Byzantine days as Blachernae, to see the Church of St Mary of Blachernae  one of Istanbul’s best-known Eastern Orthodox churches. While its exterior is nothing to shout about, the church itself is highly significant to the country’s Eastern Orthodox community with its much-celebrated status as a shrine to the Holy Virgin. Head inside to see a holy water spring.
Visit the Western District next, to see Chora Church, a spectacular Byzantine monastery. While exploring with your guide, admire its stunning mosaics that depict the life of Christ and marvel at the equally elaborate frescoes, painted in intricate detail that was way ahead of other Byzantine artwork.
Return to Ayvansaray to explore the ancient site of Blachernae Palace, and while the site is now more ‘rubble’ than palace, its ruins provide an inspiring sense of its former glory. See the outside of Anemas Dungeons, learning how it was once a terrifying Byzantine prison, and then see the exterior of Tekfur Palace (or Palace of Constantine Porphyrogenitus to give it its due)  the only surviving building of Blachernae Palace.
Finish with a walk around the Walls of Constantinople, seeing the remains of the ancient city’s old towers and gates, and then end your tour in the Sultanahmet district in the center of town.