Lost City was full of Choquequirao. Choquequirao, in fact, was Bingham's destination on his virgin trip to Peru in 1909, the city he believed to be the last holdout of the Incas during the dark days of the 1530s, when the Spanish conquistadors of Francisco Pizarro systematically destroyed their empire. City of Gold was how the Peruvians translated the name to Bingham, a guttural El Dorado. The last holdout would hold the last treasure—not to mention the thrill of danger. "In the journey to Choquequirao," Bingham wrote, "it seemed as though our heavily laden mules must surely lose their footing and roll down the fifteen hundred feet to the raging Apurímac River below."

Once Bingham decided that Machu Picchu, in fact, was the City of Gold, Choquequirao faded like a discarded high school girlfriend. But recent archaeologists have cast doubt on Bingham's theories on Machu Picchu. Choquequirao, the original City of Gold, may be getting ready for its red carpet walk.

I called Rebecca. My daughter had already fulfilled Nazario's prophecy, having returned to Peru just after college graduation to teach the local children in the town of Urubamba, up the river from Machu Picchu.

"Sure," she said. "May's good for me, I can take a day off." I replied that there's a reason Choquequirao is so unknown. It takes more than a day to reach it, and even then there's no easy way to do so. I knew some people who had flown in by helicopter, but the winds in the mountains can be vengefully unpredictable. They had nearly crashed. Three times.

"It's a five-day hike," Roger said.

"With mules?" I asked, imagining Bingham's heavily laden companions.

"Leave it me."

And so it was that at noon on an early-May day, after a four-hour drive from Urubamba, Rebecca and I found ourselves at the beginning of the trail, squatting beside a camp stove with our guide, Ana, and our cook, Felicitas, finishing up a lunch of cold chicken and cauliflower. The fifth member of our party, Carlos, our arriero (muleteer), ran after one of our three mules, which had just disappeared off the side of the road.

It was Ana who, several years before, had introduced us to Nazario and invited him on our trip to Machu Picchu. The daughter of a schoolteacher from Cuzco and a Quechua-speaking mother, she had begun guiding visitors into the rain forest of Manu and the Incan villages of the altiplano during the worst of the guerrilla violence of the 1980s. Ana knew a lot of facts—names of plants and trees and birds and historical dates—but even better, she knew a lot of rumors, a lot of folk history, tales of ghosts and apus.

For the first hour, we skipped three abreast on a wide trail. Rebecca and I looked at the broad panorama of Salcantay Mountain and the nearer glacial peak of Padreyoc across the river, and then at each other. This was lovely. Less than twenty miles to Choquequirao. Piece of cake.