Tunnel to a Lost World

During excavation for the deepest submerged tunnel in the world, engineers in Istanbul uncovered a hidden past: A preserved ancient harbor. It is the biggest maritime discovery in history, and to date, more than 30 shipwrecks from the Byzantine era have been recovered. With new findings every day including stone foundations from a settlement dating back 8,000 years construction of the tunnel has come to a halt, and the delay is costing the engineers millions. Now, National Geographic goes on site to one of the largest archaeological excavations ever undertaken and grants viewers behind-the-scenes access to this heated battle between modernizers and historians.