U.N. experts will visit to evaluate stone spheres

By the A.M. Costa Rica staff

A delegation from the United Nations will visit Costa Rica next month to evaluate those prehistoric stone spheres with an eye to including them as world heritage artifacts.

The nine members of the group all are archaeological experts, and some are experts on the spheres.

They will be visiting from March 8 to 13. Costa Rica has been promoting the spheres for a possible heritage listing. In addition to the national pride, such a listing will be a boost for tourism.

Leading the delegation is Nuria Sánez, director of world heritage for the U.N. Educational, Scientific and Cultural Organization. The Museo Nacional here said that the U.N. is considering the spheres for inclusion in the Prehistory and World Heritage category. The visitors will look at all of the Gran Chiriquí that includes the Diquís area where the spheres are located. The Gran Chiriquí is one of the three major archeological regions of Costa Rica.

Experts are in general agreement that they do not know the reasons that the spheres were made  from about 400 to 1400 A.D. or the use to which they were put. They were fabricated by the ancestors of today's Boruca Indians. They still live in the area.

There is a lot of speculation, and the possibilities suggested by those on the lecture circuit and the authors of popular books and articles include the usual assembly of spacemen, time warps and mythical creatures. The professionals are more subdued. Francisco Corrales, for example, said that he thinks the stone spheres were used to mark important buildings and the dwellings of leaders. He is the former director of the Museo Nacional who now is heading the Los Diquís project to develop a museum in Palmar Norte dedicated to the spheres.

The heaviest spheres weigh in at 20 tons. The biggest is more than 2.5 meters (about 8 feet) in diameter. Some are on display at the national museum, but Costa Ricans have been collecting the spheres for home display since they were  discovered before World War II.

Most experts believe they were created by a process of heating and cooling the stone, causing it to exfoliate in layers. According to their theory, the shape was further refined by careful chipping and finally polished through abrasion.

The spheres are almost perfectly round, deviating from the circumference by less than 1 percent.

Among those in the delegation are John Hoopes, an expert in early societies. He is a professor at the University of Kansas and has published extensively on early Central America.

Others are Helaine Silverman, a member of the International Committee on Archaeological Heritage Management;  Richard Cooke of the Smithsonian Tropical Research Institute in Panamá;  Jorge Wagensberg, a professor at the Universidad de Barcelona;  Ann Cyphers, a specialist in the Olmec civilization at the Universidad Autónoma de México;  José Luis Prada, a geologist and professor at the Escuela Superior de Conservación y Restauración de Bienes Culturales de Cataluña;  Jeffrey Quilter, a harvard University professor with specialities in the cultures of the Andes and in Central America; and Cristòbal Gnecco, an archaeology and anthropology professor at the Universidad del Cauca, Colombia.