The Stone Spheres of Costa Rica
In the jungles of southern Costa Rica, workers clearing land found hundreds of almost perfectly round stone balls.
What was reported
In the 1930s, workers clearing jungle for banana plantations in the Diquís Delta of southern Costa Rica began finding large, nearly perfect stone spheres. More than 300 are now known, from the size of a tennis ball to over 2 metres across and weighing many tonnes.
Many were moved to gardens and offices, and some were broken open by treasure hunters who believed they contained gold. Nothing was found inside.
Explanations offered
Archaeologists have shown they were made by people of the Diquís culture, shaping granite-like rock by hammering and grinding. What they were for remains unknown: suggestions include marking the homes of important people, or astronomical alignments. In 2014, the sites were listed by UNESCO.
- When
- Made between about 500 and 1500 CE
- Where
- Diquís Delta, Puntarenas, Costa Rica
- Witnesses
- Workers, archaeologists and visitors
- Status
- Purpose unknown
Famous cases are real, widely reported events. Each file sets out what witnesses said and the explanations that have been offered, without taking a side.