Ancient Mega-Fort

This episode explores the defenses of ancient forts and cities. Discover the invisible underground defensive systems of Cappadocia and how they proved so successful. Test the ancient Mayan killer bee castle defenses, and release bees in an attack. A replica section of the ancient Roman fort of Alesia is built. And the most impregnable walls in history—the multi-layered defenses of Constantinople are investigated and the type of cannon that destroyed them 1453.