🇨🇷 Costa Rica · Megalith
Diquís Stone Spheres
Chiriquí period (~600–1500 CE; peak Aguas Buenas 800–1350 CE) · Diquís (Chiriquí, Isthmo-Colombian)
Costa Rica's Diquís Delta preserves over 300 near-perfect spheres of gabbro up to 2.66 m diameter and 16 tonnes, shaped by pecking and grinding until calipers verify sphericity within 2 cm.