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. It has been shot at, exploded, set on fire, rocked by earthquakes, looted for its magnificent sculptures and subjected to restorations that have been termed "catastrophic”. Despite so much abuse and renown as an icon of Western civilisation, the question of how the Parthenon was built has been largely ignored until recently. Now, thanks to the Greek government's $10 billion restoration program, scholars are finally probing the enigmas of its planning and construction. With unprecedented access, the inside story of the official restoration, which reaches far beyond the challenges and controversies of conserving one of the world's best-known buildings, is told. The researchers confront some truly monumental riddles: How did the ancient Athenians build their great temple with incredible precision in a mere eight years? How did they manage to incorporate subtle, eye-pleasing distortions into the Parthenon's layout, such that there are few straight lines or right angles to be seen? And, most baffling of all, how did they accomplish all this without an overall building plan or blueprint, which would be indispensable to a modern architect?