Machu Picchu, Peru
Credit: Dietmar Petrausch / Getty Images

Attracting nearly one million visitors per year, one of the biggest misconceptions about Machu Picchu, according to Davis, is that it was some sort of "lost" city. "When actually it was only 'lost' in the imagination of Hiram Bingham," the American explorer-turned-U.S. Senator who rediscovered the site in 1911. "If you go to Machu Picchu, you see the evidence of the network of rural roads that connected it back to the heart of the empire," he says.

Situated 7,970 feet above sea level on the eastern slope of the Andes, the site – which was abandoned during the Spanish Conquest in 1572 (122 years after it was built by the Incas) – is a once-in-a-lifetime trip for most visitors. For Davis, who has visited Machu Picchu at least 40 times, it's also a place for personal discovery. "When you do revisit a site literally dozens of times over a lifetime, it's not just that you're learning new things about the site; you can't help but learn more things about yourself," says Davis. "In that sense, you can trace your memory to times of almost beguiling innocence to deeper levels of knowledge both of yourself and, more importantly, the place where you are."

Getting there: PeruRail offers several morning train departures from Cusco to Machu Picchu, which includes one transfer and takes approximately four hours.