Ghosts of Machu Picchu (2010) — Peru
Despite the melodramatic narration and hokey re-enactments accompanied by swelling music, this 52-minute television production by Nova and National Geographic makes for a great family night. There are so many confounding questions about the two hundred 15th-century structures cut into the terraced hills 8,000 feet high in the Peruvian Andes. The Incas only ruled for about a century before the Spanish conquered them in 1572, but their architectural legacy remains one of the world's wonders. The site gets 76 inches of rain a year, but boasts extensive drains, canals, and fountains. No mortar, wheel, or iron tools were used with the granite rock. No written language or carvings remain to explain the sacred site. And so Machu Picchu remains a "beautiful and baffling" feat of engineering, as evidenced by the thousands of tourists who trek there every year.