The stone spheres (or stone balls) of Costa Rica are an assortment of over three hundred petrospheres in Costa Rica, located on the Diquís Delta and on Isla del Caño. Locally, they are known as Las Bolas (literally The Balls). The spheres are commonly attributed to the extinct Diquís culture and are sometimes referred to as the Diquís Spheres. They are the best-known stone sculptures of the Isthmo-Colombian area.The Palmar Sur Archeological Excavations are a series of excavations of a site located in the southern portion of Costa Rica, known as the Diquís Delta. The excavations have centered on a site known as "Farm 6", dating back to the Aguas Buenas Period (300-800AD) and Chiriquí Period (800-1550 AD). In June 2014, the Precolumbian Chiefdom Settlements with Stone Spheres of the Diquis was added to the UNESCO list of World Heritage Sites.