By Matt Smith,
Elberton, Georgia (CNN) -- In the beginning, there was the stone.
The blue-gray vein of granite that courses through northeastern Georgia spawned jobs in the quarries and finishing sheds of Elberton, where generations of stonecutters have turned slabs of rock the size of refrigerators into statues, tombstones and tile.
And one day, it brought a visitor who gifted the town with a landmark that leaves visitors scratching their heads decades later.
The nearly 20-foot high series of granite slabs known as the Georgia Guidestones are inscribed with a series of admonitions for a future "Age of Reason." Billed as "America's Stonehenge," it's an astronomically complex, 120-ton relic of Cold War fears, built to instruct survivors of an Armageddon that the mystery man feared was all too near.
The identity of the man who called himself "R.C. Christian" is a secret that Wyatt Martin, the banker who acted as his agent in Elberton, vows to take to his grave.
"He told me, 'If you were to tell who put the money up for this, it wouldn't be a mystery any more, and no one would come and read it.' That had to be part of the attraction, to get people to come and read his 10 rules that he came up with," Martin said.
People in Elberton, about 100 miles east of Atlanta, are proud of their eccentric landmark. But 30 years after its dedication, it has drawn the attention of a new generation of conspiracy theorists with very different fears.
"There are a lot of people who don't feel about it the same way we do," said Phyllis Brooks, president of the Elbert County Chamber of Commerce.
The four vertical slabs that dominate the Guidestones are inscribed back and front with Christian's 10 principles, each side in a different modern language. The capstone is inscribed in the alphabets of early human civilizations -- Egyptian hieroglyphics, Babylonian cuneiform, Sanskrit and classical Greek.
The center column has a slot through which the transit of the sun throughout the seasons can be observed, while a hole higher up focuses on Polaris, the north star. Another hole in the capstone focuses a beam of sunlight onto the central pillar at noon. Those features would allow the survivors of Christian's feared apocalypse to reproduce three of the basic tools of civilization: the calendar, clock and compass.
Loris Magnani, an astronomy professor at the University of Georgia, questions how useful the Guidestones would be to survivors of civilization-ending cataclysm. The devices incorporated into the stones are "relatively easy stuff" that most human societies have developed early in their histories, he said.
"Don't get me wrong. As a monument, it's fine. There's nothing wrong with doing that," Magnani told CNN. But he added, "Every decent civilization going back to a couple of millennia before Christ has figured this out. How to make gasoline? Now that would be useful."
But it's the written messages of the Guidestones that have drawn the most criticism.
Most are innocuous, calling on readers to rule their passions with "tempered reason," avoid "petty laws and useless officials" and "prize truth, beauty, love ... seeking harmony with the infinite." They end with the advice, "Be not a cancer on the Earth -- leave room for nature."
But the first two -- which call for limiting human population to half a billion, less than 10 percent of today's numbers, and guiding reproduction "wisely" -- have led some to call the Guidestones a call to genocide and the "Ten Commandments of the Antichrist."