Prehistoric Stone Balls--a Mystery

Hundreds dot the Costa Rican jungle, as baffling as the monuments of Stonehenge.

stone balls
The author and her husband resting by one of the spheres. But for a revolution, they might never have investigated them.
stone balls
Some of the balls are more than six feet in diameter, and were moved many miles over hill and dale from the nearest source of stone. Some were even found on mountains.
stone balls
Whatever their original purpose, these round balls now decorate the lawn of the banana plantation manager, who had them placed there for ornamental effect.
stone balls
Almost all of them were carved from the local lava. Nothing has been found of any of the tools or instruments that were used in making them.
stone balls
All photos by the author and Paul Allen

As the unscientific wife of a scientist, who for years has tagged along on archaeological expeditions, I have witnessed many seemingly unexplainable discoveries, but none has provided a greater challenge or teased my imagination more acutely than the unbelievable stone balls found in Central America. The riddles they pose would threaten the deductive powers of a Sherlock Holmes.

Why should hundreds of these perfectly shaped spheres, ranging in diameter from a few inches to eight feet, be scattered through the jungles southwestern Costa Rica? How could prehistoric people have shaped them with only the crudest of tools? And how could they have moved them over hill and dale from the distant sources of stone? No other stone balls of like size have been found anywhere else in the world, except for a few in the highlands of Guatemala and in Vera Cruz. The smooth, beautiful and almost perfectly rounded spheres give mute testimony to the artistic powers of an ancient people and tax modern man’s ingenuity in explaining their workmanship and significance.

My acquaintance with them came about by pure chance.

A few years ago, my husband and I had made plans to spend the winter digging in a small Costa Rican town called Filadelfia, near the Nicaraguan border; where we had begun work the winter before. We reached Costa Rica prepared for any emergency, or so we thought, but we had overlooked the possibility of a revolution. There had been shooting and a few murders near the Nicaraguan frontier, bandits were taking advantage of the situation to loot the countryside, and Filadelfia might well be on their route.

We wanted to keep to our plan, but the Lothrops were not thought to be worth a possible international incident, and Filadelfia was declared definitely out of bounds.

Two weeks after our arrival in Costa Rica, we were comfortably ensconced in the house of friends in San José, with no apparent prospect of getting any further. Neither Sam nor I was happy. We were feeling especially desperate one day when our hostess came forth with the magic word.


Palmar? What’s that? asked Sam.

A banana plantation on the Panamanian border, she answered.

“And what do you find there besides bananas?” asked Sam, without much enthusiasm.

“Well,” said our hostess, “there may be ancient burials, although I’m not entirely sure. But there are some very strange stone balls—obviously prehistoric, though no one knows what they represent or where they come from.””

“No one knows?” said Sam. His eyes lit up, and his face took on the look of a bloodhound about to be let loose on the scent. After all, the work of an archaeologist and a detective is basically the same, with the small difference that a detective gets much better pay.

“Let’s go to Palmar,” said Sam. At Palmar, we found that the United Fruit Company had built an elaborate settlement for their employees in the midst of a steaming jungle some twelve miles from the Pacific coast. We were allotted the comfortable house of a vacationing employee and were soon looking for the stone balls. We didn’t have far to go. Next door was the house of the company manager, and beyond it a public park. In the exact center of the park was a perfectly rounded sphere about three feet in diameter.

“Sam, we’ve found it,” I cried, feeling like Archimedes, or perhaps Mrs. Archimedes.

“It!” exclaimed the company manager. “Why, there are lots of them. Are you interested?”

We admitted we were very much interested, and the company manager straightway took us on an inspection tour. We crisscrossed thousands of acres under cultivation, and the countryside fairly teemed with stone balls. The company manager seemed to know each one personally and stopped the car six or seven times for us to get out and take notes. A few days later we started work in earnest.

In two months we examined 60-odd balls in their original locations; some underground where they had been covered with silt from overflowing rivers. There must have been hundreds or even thousands we didn’t see. There were also great chunks of rock, the remains of balls that superstitious natives had blasted to bits in the belief that they might contain gold.

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