The Diquis disappeared long ago, thought to have been absorbed by an influx of peoples from South America. A single trail on Caño Island leads to what is thought to be a Diquis burial ground, marked by some of the pre-Columbian granite spheres that dot the landscape of the Diquis Delta, which covers the coastal region south of Quepos and the upland valleys southwest of the Talamanca Mountains. Nearly perfect spheres, some are small enough to hold in the hands, others several feet in diameter and likely the archetype for the sphere that almost overruns Indiana Jones in the 1981 movie Raiders of the Lost Ark.
The purpose of the stones remains unknown, although they are often found near ancient cemeteries. More recent speculation is that they might have been used as landmarks to help the native people navigate the dense jungle where it’s easy to get turned around.
How the Diquis formed these spheres that appear perfectly round is equally unknown; measurements have to be taken to detect any variation from the spherical. And the Diquis somehow transported stones that weigh tons to their locations—the granite from which most were carved is not present where the spheres are found. One of the world’s archeological mysteries, the spheres have been discovered in the hundreds. Those on Caño Island are some of the few known to still reside on their original locations. Many more surely lie buried throughout southern Costa Rica.