Secrets of the Parthenon

NOVA: Erected by the ancient Greeks as a temple to Athena, the Parthenon has served as a church, a fortress, an ammunition dump and the model for countless banks, courthouses and museums across the world. The inside story of its official restoration reaches far beyond the challenges of conserving one of the world's best-known buildings as researchers confront some monumental riddles. For example, how did the ancient Athenians build their great temple with incredible precision in a mere eight years?