Digging for the Truth

Machu Picchu: Lost City of the Inca (3x6)

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In 1911, Hiram Bingham, famed American explorer, stumbled across a remote Inca city atop a high peak in the Andes. The site was called Machu Picchu--perhaps the most famous ruin in the world. Was it, like Bingham believed, a military fortress or did this glorious ruin have a secret purpose?