4) Hagia Sophia
Hagia Sophia means “Holy Wisdom” in Greek. This monumental structure was once an Orthodox patriarchal Basilica, then a mosque, and now, finally, is a Museum in the city of Istanbul. It was built in the fourth century by Constantine the Great as a Church, and it has seen much of the changing ruling powers of Istanbul ever since.
Many people mistake it as being dedicated to Saint Sofia, but the church was originally dedicated to the second person of the Holy Trinity, and its full Greek name...
Image Courtesy of Wikimedia and Gokhan