In Elbert County, Georgia there’s a set of stones called the Georgia Guidestones. They were put there in 1979, with a set of ten guidelines, in eight modern languages and four dead ones, carved onto the slabs. But that’s pretty much all anybody can agree on about them, as Jill Neimark writes this week at Discover Magazine. How to interpret the guidelines, who put the stone there, and what people should do about them are all hotly debated.

On the stones are ten instructions:

Maintain humanity under 500,000,000 in perpetual balance with nature. Guide reproduction wisely — improving fitness and diversity. Unite humanity with a living new language. Rule passion — faith — tradition — and all things with tempered reason. Protect people and nations with fair laws and just courts. Let all nations rule internally resolving external disputes in a world court. Avoid petty laws and useless officials. Balance personal rights with social duties. Prize truth — beauty — love — seeking harmony with the infinite. Be not a cancer on the earth — Leave room for nature — Leave room for nature.

Neimark visited the stones and writes about the mystery behind them. The only man who knows who built them isn’t telling, “They could put a gun to my head and kill me, I will never reveal his real name,” he told her. And the purpose of the inscriptions isn’t even clear. Van Smith, “one of the monument’s most prominent conspiracy theorists,” says that they’re for establishing the beginnings of a totalitarian tribal government. Another theorist said that the stones were Satanic and should be destroyed. Alex Jones, a radio host and famous conspiracy theorist, says that the stones call for culling of humans.

Many hate the stones. When Randall Sullivan of Wired visited the stones in 2009, they had been vandalized, “Death to the new world order” painted on them in polyurethane paint.

Not only were the stones supposed to give messages, but their arrangement was meant to be a Stonehenge like astronomical device. Sullivan writes that the man commissioned to build them had to seek outside help to make that dream a reality:

The astrological specifications for the Guidestones were so complex that Fendley had to retain the services of an astronomer from the University of Georgia to help implement the design. The four outer stones were to be oriented based on the limits of the sun’s yearly migration. The center column needed two precisely calibrated features: a hole through which the North Star would be visible at all times, and a slot that was to align with the position of the rising sun during the solstices and equinoxes. The principal component of the capstone was a 7\8-inch aperture through which a beam of sunlight would pass at noon each day, shining on the center stone to indicate the day of the year.

But today, astronomers say the astronomical features on the guidestones are crude—”an abacus compared to Stonehenge’s computer,” Loris Magnani of the University of Georgia told Neimark.

And yet despite the confusion and mystery—or perhaps because of it—the monument has a devoted community dedicated to figuring out just what the mysterious rocks are for. And, like most conspiracy theories, the quest will probably never end.

More from Smithsonian.com:

Did Dinosaurs Build Stonehenge?

Digital Laser Scans of Stonehenge Reveal Ancient Graffiti