Genre: Documentary, History, Science
Premise: A camera crew descends hundreds of feet below the streets of major cities -- such as New York, Cairo, London and Tokyo -- to explore the layered remnants of civilizations left buried deep under modern metropolitan centers.
S01, E06 (First Aired: May. 21, 2007)
Beneath the city of Budapest, Hungary.
S03, E06 (First Aired: Dec. 1, 2008)
Host Don Wildman tracks down subterranean secrets from Europe's Dark Ages, including a secret society's immense quarries, Templar torture chambers and the tunnels of medieval ``ghost knights.''