Walk in the footsteps of some of the earliest Christians and discover the Orthodox heritage and centuries-old churches of Istanbul. With a private guide leading the way, delve into the roots of Christianity as you visit landmark churches and shrines from the Patriarchate of Fener by the Golden Horn to the Hagia Sophia.

Your guide picks you up right from your hotel and kicks off your outing with a discussion of Istanbul's past, as the Christian capital of the Roman Empire under Constantine and as the home of the Orthodox Catholic Church since the Middle Ages. Begin at the Ecumenical Patriarchate of Constantinople, the Mother Church of modern Orthodox churches, and visit the tiny 19th-century Church of Panagia of Blachernae to hear about the shrine to the Virgin Mary that once stood on this site.

Study the Byzantine-era mosaics and frescoes of the Chora Church, hear about the important monastery complex of Christ Pantokrator, now a mosque, and make your way to the 6th-century pilgrimage site of the Church of St. Mary of the Spring. Stand before the domed church known as Little Hagia Sophia before visiting the grander structure of the same name, a cathedral-turned-mosque-turned-museum that's among Istanbul's most famous landmarks. Finally, travel back in time at the Hagia Irene. Dedicated by Constantine himself in the 4th century and supposedly set atop an earlier Christian temple, the Hagia Irene is the first church built in Constantinople.