Step into the past and discover the traces of early Christianity on display among Istanbul's Islamic mosques and Eastern Orthodox institutions. Learn about the roots of religion as you visit ancient structures, admire Byzantine architecture, and stand where pilgrims have walked for centuries.

After you're picked up from your hotel, listen as your guide describes the complex religious history and identity of Istanbul. Learn about its role as the Christian capital of the Roman Empire, and hear about the schism that split the Roman Catholic Church and the Orthodox Catholic Church in the 11th century. 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.

Explore the sprawling monastery complex of Christ Pantokrator, and study the well-preserved Palaiologan architecture and beautiful mosaics of the Pammakaristos Church. Depending on the day, the highlight of your outing could be the Chora Church—famed for its striking frescoes—or the Hagia Sophia, the iconic cathedral-turned-mosque that's dominated Istanbul's skyline since the 6th century.