9.0000°N, 83.5000°W.
Approximately 300 stone spheres distributed across the Diquís Delta of southwestern Costa Rica, ranging from 0.05 to 2.66 metres in diameter and weighing up to 16 tonnes. The largest are nearly perfect spheres with surface deviations under 0.5%. Composed of gabbro and granodiorite quarried in the Talamanca Mountains 50 km away. The Diquís culture (also called the Aguas Buenas and later Chiriquí) produced them between approximately 600 and 1500 CE. Most were discovered in the 1930s during United Fruit Company banana plantation clearance; many were dynamited by treasure-hunters who believed the spheres contained gold. Of the original number documented, fewer than 100 remain in their original locations. The carving technique remains debated; the working tools that produced them have not been recovered. UNESCO World Heritage 2014.
A pre-Columbian people made spheres accurate to within half a percent across two metres in granite — and the United Fruit Company blew up most of them looking for gold.