Nature is an infinite sphere of which the center is everywhere and the circumference nowhere. —Blaise Pascal
Scattered around San José—and the rest of Costa Rica, for that matter—are stone spheres of various sizes, dating back during the Pre-Columbian era. No one is absolutely certain what their purpose was for, but it is thought that a sphere's size indicated the social standing of its owner, and no doubt the carvers of these spheres were experts in stonecutting and hands-on geometry.
Housing a medium-sized sphere in front of the Museo Nacional is a more contemporary one that's no less enchanting than the stone one.
I'm glad to see we haven't lost our fascination with platonic solids…