Over three hundred petrospheres in Costa Rica, are located on the Diquís Delta and on Isla del Caño. Locally, they are known as Las Bolas. They seem randomly distributed but with bird’s eye view one discovers patterns believed to be the mirroring of certain constellations. The stone balls are made of hard rock, often granite, and have true spherical shape in most cases. There are small ones but the bigger balls are larger than 2 meters (6.6 Feet) in diameter and weigh many tons. Some weighing in at 15 tons.
However, many of the balls have been removed from their original positions and taken to gardens and public parks for decoration purposes. So it's virtually impossible to examine the original collective alignment. Furthermore, many of the stone balls were demolished in search of treasure as it was believed that they contained gold or other valuables