These ancient stone spheres are an assortment of over 300 petrospheres in Costa Rica, on the Diquís Delta and on Isla del Caño. Locally, they are also known as bolas de piedra (literally stone balls). The spheres are commonly attributed to the extinct Diquís culture, and they are sometimes referred to as the Diquís Spheres.

The stone spheres of Costa Rica are an assortment of over 300 petrospheres in Costa Rica, on the Diquís Delta and on Isla del Caño. Locally, they are also known as bolas de piedra (literally stone balls).

They are thought to have been placed in lines along the approach to the houses of chiefs, but their exact significance remains uncertain.

The Palmar Sur Archaeological Excavations are a series of excavations of a site located in the southern portion of the country, known as the Diquís Delta, and have centered on a site known as “Finca 6” (Farm 6). The archaeological findings date back to the Aguas Buenas Period (300–800 CE) and Chiriquí Period (800–1550 CE).

In June 2014, the Precolumbian Chiefdom Settlements with Stone Spheres of the Diquís was added to the UNESCO list of World Heritage Sites.[1] In July 2014, a project, which had been proposed in 2011, to declare the spheres a national symbol of the country was approved.[2]

According to some archaeologists’ hypothesis the spheres could represent solar systems or just be inspired by various stages of the sun and the moon as viewed with the naked eye, including setting or rising suns, and half moons.

The spheres range in size from a few centimetres to over 2 metres (6.6 ft) in diameter, and weigh up to 15 tons.[4] Most are sculpted from gabbro,[4] the coarse-grained equivalent of basalt. There are a dozen or so made from shell-rich limestone, and another dozen made from a sandstone.

They appear to have been made by hammering natural boulders with other rocks, then polishing with sand. The degree of finishing and precision of working varies considerably. The gabbro came from sites in the hills, several kilometres away from where the finished spheres are found, though some unfinished spheres remain in the hills.[citation needed] They are used for decoration.

The archaeological site of Palmar Sur is located in the southern portion of Costa Rica, known as the Diquís Delta, and in the southernmost part of the Puntarenas Province. The Diquís Delta is defined as the alluvial plain with the geographical boundaries of the Fila Grisera to the north and east, the Pacific Ocean to the west, and the Osa Mountains comprising the southern boundary.

The spheres range in size from a few centimetres to over 2 metres (6.6 ft) in diameter, and weigh up to 15 tons.[4] Most are sculpted from gabbro,[4] the coarse-grained equivalent of basalt. There are a dozen or so made from shell-rich limestone, and another dozen made from a sandstone.

They appear to have been made by hammering natural boulders with other rocks, then polishing with sand. The degree of finishing and precision of working varies considerably. The gabbro came from sites in the hills, several kilometres away from where the finished spheres are found, though some unfinished spheres remain in the hills.[citation needed] They are used for decoration.

The archaeological site of Palmar Sur is located in the southern portion of Costa Rica, known as the Diquís Delta, and in the southernmost part of the Puntarenas Province. The Diquís Delta is defined as the alluvial plain with the geographical boundaries of the Fila Grisera to the north and east, the Pacific Ocean to the west, and the Osa Mountains comprising the southern boundary.

The Site is located in Palmar Sur, southern Costa Rica. The site is located on approximately 10 hectares of property that was previously owned by the United Fruit Company in the alluvial plain of the Térraba River.

The archaeological site of Farm 6 has been dated to the Aguas Buenas Period (300–800 CE) and Chiriquí Period (800–1550 CE). It was a multifunctional site accommodating a settlement and a cemetery, and remains of monumental architecture and sculpture are also present on the site. The monumental architecture consists of two mounds which were constructed with retaining walls made of rounded river cobbles and filled with earth.

The site contains multiple locations where large stone spheres are found in situ. Additionally, since many of the stone spheres in the region were removed from their original locations and serve as landscape decoration, the site has become a storage location for spheres that have been returned to the National Museum. One of the neighboring towns to Farm 6 also had spheres or “esferas”. They were called “zanahoriagas”, for their more oval-like shape.