One of the strangest mysteries of archaeology concerns the mysterious stone spheres found in various places on the planet. One of these places, in terms of numerical importance of the spheres, is Costa Rica , and more precisely in the area of the Diquís delta and on Caño Island .
In this region, since 1930 , over 300 mysterious petrospheres , stone spheres called “Las Bolas”, have been found, ranging in size and diameter from a few centimetres to over two metres . Some weigh 16 tons . Almost all are made of granodiorite, a very hard igneous stone made by human hands. No incomplete or empty spheres have ever been found. Universally associated with the now extinct Diquís culture , these bizarre finds are quite well known in the academic world precisely because their function is unknown. Those who created these stone objects began to emerge as a pre-Columbian indigenous culture as early as 1500 BC , around the Térraba River Valley and transported from there, through natural processes, from the Talamanca Mountains
The Diquís culture had its roots here and began to form small agricultural communities, with a tribal social structure very similar to that of many other indigenous civilizations in Latin America. The real moment of affirmation came between 300 BC and 800 AD , when the settlements expanded, an increasingly centralized control by a single authority began to take effect and trade with other populations increased. It was precisely in this long period that the Diquís began to produce the first stone sculptures, including some cylinders, some characters from their tradition. Between 800 and 1500, the peak of cultural and technological development was reached, thanks to the unrestrained expansion of the communities around the banks of the Térraba River. The evidence of this incredible step forward is presented to us by archaeological research, which has brought to light various gold, ceramic and bone finds, as well as increasingly complex burial sites. During this period, the production of Costa Rican stone spheres reached its maximum level, achieving perfect shapes with spheres over 2 meters in diameter and a maximum weight of 15 tons .
