Donnan and his archeological team unearthed the treasure-filled tombs, dating from the ancient Moche culture, in a 105-foot-high pyramid on a site known as Dos Cabezas on the coast of northern Peru. With an anthropologist's keen eye and a few intuitive "hunches," Donnan led the team to their discovery over a period of six years.
Donnan had been excavating the remains of Moche culture for 35 years when he brought his team to the pyramid in 1994. For three years between June and September, they excavated skeletal remains and objects left behind by looters of nearby graves.
"We learned a lot about funerary practices," Donnan said, "but I was hopeful that we might be able to find an unlooted tomb in the pyramid itself. I had a hunch."
In the summer of 1997, four hours into the first day of excavation, they found such a tomb "exactly where I thought it would be," Donnan said. "It was an educated guess … and a lot of luck."
What they found were the remains of an adult male in a metal headdress and a gold nose ornament, with a 15-year-old female sacrifice at his feet and museum-quality ceramics in the tomb's corners.
"The discovery was wonderful," Donnan said. "It was thrilling."
When he returned to UCLA, the anthropologist mused about some vertical cracks he'd noticed in the brick above the tomb, similar to cracks in a wall immediately north.
"I thought it possible that there was going to be another tomb," he noted.
In June 1998, at the end of the second day of excavation, Donnan's team hit upon a second more elaborate tomb just north of the first one. The following summer, they found a third tomb. "It was incredible," Donnan said.
The archaeologist believes they have now uncovered the "full set," an achievement that has helped put his anxieties about grave robbers to rest.
"I sleep in these tombs every night, from the time we open the burial chamber until excavation is complete," he revealed. "To tell you the truth, it's the only place that I'm confident that I can get a good night's sleep.
"These are the richest Moche tombs ever found. If I were anywhere else, I'd be wondering if anything is happening, if anyone is rifling through the tomb."