Inexplicable and perfectly spherical stones of Costa Rica
They are known as Las Bolas (“bullets”) and are 15 centuries old. Archaeologists agree that the spheres were created by the Diquis culture, a civilization that died out before the Spanish conquest. They vary from 10 to 257 cm in diameter and weigh more than 16 tons for some. Bullets have been forged and scattered all over Costa Rica over a 1000-year period, and although scientists know who made them, their purpose and reason for their location remains unknown.