Last week, we visited the World Heritage Site that contains pre-Columbian era stone spheres. Locally known as "Finca 6", there's a museum and outdoor walking paths that pass active archaeological sites, as well as unearthed and partially unearthed spheres, several in their original locations. The finca (farm) is located in Southern Costa Rica.
Although many of the spheres have previously been stolen, moved and/or vandalized, some have been discovered untouched, safely preserved below ground - covered for centuries by Rio Terraba river sediment that was left behind by retreating flood waters.
The spheres are constructed of gabbro and granodiorite, types of igneous (lava) rock, as well as sandstone and limestone (both sedimentary rocks). They range in size from a few centimeters to 2.57 meters in diameter, weighing up to 24 tons. It's thought that the spheres symbolized rank, power and ethnic identity of the region's native people. Production of the spheres began in approximately 300 a.d. , although how, exactly, they were made, remains a mystery. 