Why the people of pre-Spanish colonisation Costa Rico decided to carve 300 giant balls of stone is as much a mystery today as it was when the balls were discovered. Some are as large as two metres in diameter.

Now dated to between 600 & 1000ad. Spanish settlers ensured the indigenous population's cultural heritage was wiped out.

Does anyone know if the stones had markings (i.e. symbols) om them?
Any ideas on why these spheres were made?