"I WOULD SAY THERE ARE PROBABLY three types of people involved in the pyramids," says Anthony Harding, professor of archaeology at the UK's University of Exeter and president of the European Association of Archaeologists. "There are fanatics who want to believe this stuff, there are people who are being misled, and there are people who are leading people along, cynically, for political and financial reasons."

Osmanagic seems like a true believer to me, but the four young Bosnian bloggers behind the AntiPyramid Web Ring prefer a different term: Pyramidiot. Other detractors point out that, prior to launching the Visoko dig, Osmanagic had spent 15 years exploring loopy theories of alternative history. He has written several books on fringe archaeology, including 2005's World of the Maya, which ponders the idea that the Maya were descendants of aliens from the Pleiades star cluster. He told me he submitted a paper on the Maya as his Ph.D. thesis to the University of Sarajevo two years ago. He's still waiting for the degree.

Osmanagic was born to a Croat mother and a Muslim father. He grew up in Sarajevo, where he earned two bachelor's degrees and a master's in international economics. Like many Bosnians with money, he fled the country in the early nineties, before the war. While Sarajevo burned, he built a lucrative metal-fabrication business in Houston that eventually had him overseeing 100 employees. His wife, Oksana, is a clerk; they have an 18-year-old son.

After his flash of insight atop Visocica in April 2005, Osmanagic started cutting checks to pay for some exploratory excavations, a PR manager, and, later, satellite and thermal analysis. (He says he's contributed about $100,000 to the project to date.) Then, in January 2006, he launched the Bosnian Pyramid of the Sun Foundation Web site, which soon started indulging in a naughty habit: announcing project support from foreign archaeological authorities who either weren't supportive or weren't authorities. Royce Richards, an Australian archaeologist who'd e-mailed a simple query about the dig, found himself listed on the foundation's "advisory committee of experts." The same thing happened to Irish archaeologist Grace Fegan.

Last June, an Egyptian geologist named Aly Barakat vouched for the authenticity of the Pyramid of the Sun, claiming that he'd made the trip there on the recommendation of Zahi Hawass, the secretary-general of Egypt's Supreme Council of Antiquities and one of the leading pyramid experts. When Hawass heard this, he wrote an angry letter to Archaeology magazine, stating that he hadn't sent Barakat, who "knows nothing about Egyptian pyramids," and calling Osmanagic's theories "purely hallucinatory . . . with no scientific backing." That same month, 26 academics signed a petition to UNESCO—which had announced plans to send investigators—denouncing the "pseudoarchaeological project."

Despite the criticism, Osmanagic has gotten good international press, thanks to some rather lazy reporting. An early Associated Press article, which was broadcast by major news organizations all over the world, made the dig sound like a bona fide project and called Osmanagic an "archaeologist who studied the pyramids of Latin America for 15 years." Last fall, I watched Osmanagic record a video statement from the safari-vested Ibrahim Aly—"I don't know yet if this is a pyramid. What I do know is the fact that this structure is man-made"—that, by the end of the week, was moving on AP under the headline "Archaeologist Backs Dig at Bosnia Hills."

When journalists visit Visoko, Osmanagic likes to show off the long stone terraces on the Pyramid of the Moon. Because the stones are cracked in roughly perpendicular lines, they do bear the superficial appearance of being man-made. But look closely and you notice that the "paving stones" are all different sizes. I ask Osmanagic why the ancient engineers who needed thousands of pavers hadn't used one standard shape. "That's how we would do it today, but that doesn't mean it's the best way," he tells me. "They were a super-civilization. I'd like to have all the answers now. Unfortunately, I have much more questions."

Serious scientists have no questions. Archaeologists note that Osmanagic hasn't uncovered a single artifact and that his estimate that the pyramids are 12,000 years old—7,000 years older than any other earthly pyramid—contradicts research showing that Bosnia at that time was just coming out of the last ice age and populated by a small number of hunters and gatherers. Geologists, meanwhile, say the angular, terraced hills around Visoko are merely the remains of a Miocene lake bed that was thrust upward by tectonic forces millions of years ago. Any interior passageways are likely old mining tunnels, though there's no agreement on what the miners were after or when the shafts were created.

Osmanagic waves off the doubts. What he can't understand, though, is why scientists are giving him such a hard time. "If you really believe there are no pyramids, then it should be in your interest to help this guy so that he can dig and find nothing," he argues. "How can you disprove his hypothesis except through digging?"