Hundreds of stone balls have turned up in the delta of the Térraba River, also known as the Sierpe, Diquís, and General River as well as near the towns of Palmar Sur and Palmar Norte. Balls are known from as far north as the Estrella Valley and as far south as the mouth of the Coto Colorado River. That's a lot of territory to cover. What they were used for no one knows, but they range in size from roughly the size of a softball to as large as a Volkswagen. Who made them exactly is a mystery . How they were made has been open to much speculation since their discovery in the 1940s.
