In Bosnia, in a forest outside the town of Zavidovici, a controversial archaeologist, Semir Osmanagic, has found a giant stone sphere. It’s impressively large—four to five feet in diameter, and has high iron content. Only part of it was peaking out of the ground, but Osmanagic and colleagues revealed more of it.

This could be, he told reporters, the oldest stone sphere made by humans.

“Dr Osmanagic believes the sphere proves the existence of an advanced lost civilisation dating back more than 1,500 years ago,” the Telegraph reports.

There’s a lot going on here. First, Osmanagic. The last time he made major news was a decade ago, in 2005, when he announced he had found ancient pyramids linked by underground tunnels in Bosnia. They were connected to a 12,000-year-old civilization, he said. Other archaeologists who took a look found evidence of human habitation there, but going back just to the Middle Ages, or thereabouts. The hills, they thought, were just hills. No pyramids here.

Second, stone spheres. There are incredibly, hand-crafted stone spheres in the world. They’re found in Costa Rica, carved from a rock called gabbros. They were thought to be made from around 600 to 1000 A.D. and first came to the attention of Westerners when workers for the United Fruit Company found them in a jungle being cleared for banana plantations.

The stone sphere in Bosnia is about twice the size of the Costa Rican spheres. But it’s not the first one that’s been found there. There are a handful of smaller spherical stones that were found previously. You can see Osmanagic giving a tour of them a few years back:

Another account of a tour of the spheres, going back to 2007, has Osmanagic giving a more out-there account of the spheres:

In Zavidovici, we were to examine supposedly as Semir stated to us, man-made (or alien made—descendants of an ancient civilization from the Pleiades) perfect spherical stone balls. These perfect spherical stone balls are used for energy and near the time of 2012, will be re-energized if human’s consciousness is elevated high enough to create a vibration sympathetic to those of the balls, and beams of cosmic energy will manifest. The spherical balls have a purpose, that is, they are tools of super technology made from natural material, emanating high cosmic vibrations that will attune us (humans ) to a higher dimension…However, Semir speaks quite differently now (after our visit to Bosnia) about the spherical stone balls then he did let’s say about 2 months before-hand and is more reserved about aliens and high technology stone spheres (he now states he does not know their purpose).

If the rocks weren’t made by people or aliens, where did they come from? According to the Telegraph, geologists think they could have been created by a natural process, concretion, or a ”precipitation of natural mineral cement within the spaces between sediment grains.” So, it’s that, aliens, or a society that’s either 1,500 years old or maybe 12,000 years old. Wherever they came from, that big one is pretty cool.

Bonus finds: A 1911 ad for the Titanic

Every day, we highlight one newly found object, curiosity or wonder. Discover something amazing? Tell us about it! Send your finds to sarah.laskow@atlasobscura.com.