Istanbul: This morning I did a tour of the world's first megachurch. The Hagia Sophia (Aya Sofia in Turkish), opened in 537AD. The original name given to the first construction of this church (360 AD) was "Megalo Ecclesia". Translation: MEGA CHURCH.
Hagia Sophia is one of the Top 20 largest churches in the world if you measure the square footage but only has room for 10,000 people. Its so tall that some people say you could stand the Statue of Liberty under the dome without a problem and there would still be room for Notre Dame. It's now a museum and no longer functions as a church. In fact, when the Moslems took it over in 1453, they covered up the mosaics with plaster and paint. But as a museum the images are allowed and gradually the mosaics are coming back into public view.
Last year I took my family to a different kind of megachurch - Lakewood Church in Houston, Texas. Seating for 46,000 but not nearly as grand as the Hagia Sophia.
I used to be quite harsh in my critiques of modern-day megachurches but have since softened and become quite ecumenical. One book that opened my eyes and made me repent of some of my biases was Beyond Megachurch Myths: What We Can Learn from America's Largest Churches (Jossey-Bass Leadership Network Series).