Costa Rica’s Mysterious Stone Spheres
BY AWAKE! CORRESPONDENT IN COSTA RICA
AS LONG AS 16 centuries ago, the natives of southwestern Costa Rica made a variety of solid stone spheres, some as small as four inches [10 cm] in diameter and others up to eight feet [2.4 m]. They are so perfectly formed that one is bound to wonder, ‘How were they made? What purpose did they serve?’
Rock spheres have been found in several other countries, including Chile, Mexico, and the United States. But Costa Rica’s granite spheres are unique. Their quality is superb, some being perfect spheres with smooth surfaces. They have often been found in groups of 20 or more. Of special interest is the fact that many of them are found aligned in geometric patterns, such as triangles, rectangles, and straight lines. These alignments often point to the earth’s magnetic north.
Several spheres have been discovered in the Diquis River Delta. Others have been found near the southern cities of Palmar Sur, Buenos Aires, and Golfito as well as in the province of Guanacaste to the north and in the central valley. Several artifacts found with the spheres have provided valuable clues for dating them. Archaeologists estimate that some of these mysterious rocks date back to 400 C.E. The greatest number appeared between 800 and 1200 C.E. Some have been found near what seem to have been dwellings or in close proximity to graves. Over the years, some spheres have been destroyed by people who expected to find treasures hidden inside them. Still, the National Museum of Costa Rica has a catalog of some 130 existing stone spheres. But there are many more that are not cataloged. It has been difficult to count these ancient spheres because many have been removed from their original sites and placed as ornaments in private locations, such as gardens and churches. Undoubtedly, many lie yet undiscovered—some underground, others in thick jungles.
How were they made? This is a mystery. Some mechanical procedure seems to have been necessary in order to achieve such precision. Judging by the many statues of that period, we know that the sphere makers were skillful sculptors. In addition, gold artifacts dating from as early as 800 C.E. give evidence that they were experienced in working with high temperatures. One theory is that the sculpting of the orbs could have involved the use of high temperatures followed by cooling, to remove outer layers of rock. The work could have been finished by polishing the spheres with sand or leather.
One scientist explained that the larger spheres “were the product of the finest craftsmen, and [the spheres] were so nearly perfect that the tape and plumb-bob measurements of diameters did not reveal imperfections.” This exactness points to mathematical ability, advanced knowledge of stone carving, and use of tools on the part of the native peoples. However, since these people apparently did not have a written language, there are no records of exactly how they made the spheres.
Most of these spheres are made of granitelike rock. The nearest known granite quarry was up in the mountains about 25 to 30 miles [40-50 km] from the Diquis River Delta. How did the sculptors move such heavy stones? If the spheres were carved at the quarry, the sculptors would have had to control their descent carefully. Can you imagine the challenge of moving something so heavy across such distances without modern equipment? Exactly how heavy are the spheres? Some weigh over 16 tons!
If the granite was quarried and moved before it was sculpted, the nine-foot [2.7 m] cube that would be needed for a ball eight feet [2.4 m] in diameter would weigh over 24 tons! Likely, to create a wide, smooth road to make transport possible, the natives would have had to cut through dense jungle. No small feat! Other spheres were made of coquina, a material much like limestone, which can be found on beaches near the mouth of the Diquis River. This may indicate that the stone was rafted about 30 miles [50 km] upstream. Some spheres have been found on Caño Island, about 12 miles [20 km] off the Pacific coast.
No one can explain with certainty the original purpose of these spheres. They could have been a mark of rank or importance for a tribal chief or a village. It is also possible that they were religious or ceremonial symbols. Future archaeological studies may someday reveal the mystery of the stone spheres of Costa Rica.
[Map on page 22, 23]
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Mountain High Maps® Copyright © 1997 Digital Wisdom, Inc.
[Picture on page 23]
Locomotive behind sphere indicates scale
Courtesy of National Museum of Costa Rica
[Pictures on page 24]
Spheres on premises of National Museum of Costa Rica
Largest sphere yet found to date, with a diameter of 8.5 feet
Courtesy of National Museum of Costa Rica