Photos June 19, 2016, Submitted by Marnie L. Hutcheson (shadygrovepreserve.com)
The Bosnian Stone Sphere Park near the town of Zavidovici, Bosnia and Herzegovina, was opened in September of 2006 by the Bosnian Pyramid of the Sun Foundation in conjunction with a group of local enthusiasts who recognized the value of the stones and the need to protect them. It is located 80 Kilometers North of The Bosnian Pyramid of the Sun in Visok.
The spheres were discovered in 1936 after a large storm caused heavy runoff in the area that opened the hillside and washed out the estimated 80 stone spheres. Some of the spheres were washed all the way to the Bosna river, but most remained in the area that is now the park.
In the 1960's and 1970's many of the spheres were destroyed when a rumor circulated that they had gold inside. Spheres were also taken from the site by collectors. Consequently, today the park is mostly made up of pieces of broken spheres, with only a few remaining intact.
The balls ranged in size from several centimeters to as much as 4 meters in diameter and weighed as much as 20 tons, this largest size is based on pieces remaining at the site. The spheres are shiny and very smooth on the outside. Materials analysis revealed that the spheres are made of the same material as the local native sandstone, but contain additional materials that are consistent with binding and hardening used rock during a geopolymer casting process. Essentially it appears that the spheres were created from powered or melted local stone mixed with a calcium carbonate (binder) and manganese (hardner), then molded into the sphere shapes. Stone spheres in other parts of the world made of granite and other hard natural stones are typically "shaped" into their spherical form.
Stone spheres have been discovered in 8 different locations in Bosnia and Herzegovina. The stone spheres in Northeastern Bosnia are made of Granite, and those in central Bosnia are made of volcanic stone, these geopolymer spheres are the third type of material discovered.
Prior to the formation of the park, the area had been used as a dumping site for used appliances and other trash. Local citizens have done a great job of cleaning it up and restoring the area to a natural setting.
See also, "Dr. Semir Osmanagich Talks about the Bosnian Stone Spheres" https://youtu.be/QuGSAgxv-AY
The largest Bosnian stone sphere is only a short drive from the Bosnian Stone Sphere Park in Podubravlje village near Zavidovici. This stone sphere is the largest one found on the earth (so far). It has a diameter of approximately 3 meters and its weight is estimated at about 60 tons. Only small portion of the sphere was exposed until March of 2016 when it's excavation began and it was officially "discovered." by Dr Semir Osmanagich. Currently this giant stone sphere is the only stone sphere found in its area. At this writing, material analysis has not yet been conducted on the sphere.