The spheres were discovered in the 1930s as the United Fruit Company was clearing the jungle for banana plantations.
Workmen pushed them aside with bulldozers and heavy equipment, damaging some spheres.
Additionally, inspired by stories of hidden gold, workmen began to drill holes into the spheres and blow them open with sticks of dynamite.
Several of the spheres were destroyed before authorities intervened.
Some of the dynamited spheres have been reassembled and are currently on display at the National Museum of Costa Rica in San José.

The first scientific investigation of the spheres was undertaken shortly after their discovery by Doris Stone, a daughter of a United Fruit executive.
These were published in 1943 in American Antiquity, attracting the attention of Samuel Kirkland Lothrop of the Peabody Museum at Harvard University.
In 1948, he and his wife attempted to excavate an unrelated archaeological site in the northern region of Costa Rica.
The government had just disbanded its professional army, and the resulting civil unrest threatened the security of Lothrop's team.
In San José he met Doris Stone, who directed the group toward the Diquís Delta region in the southwest ("Valle de Diquís" refers to the valley of the lower Río Grande de Térraba, including the Osa Canton towns of Puerto Cortés, Palmar Norte, and Sierpe) and provided them with valuable dig sites and personal contacts.
Lothrop's findings were published in Archaeology of the Diquís Delta, Costa Rica 1963.

In 2010, University of Kansas researcher John Hoopes visited the site of the Stone Spheres to evaluate their eligibility for protection as a Unesco World Heritage Site.
The spheres were discovered in the 1930s as the United Fruit Company was clearing the jungle for banana plantations. Workmen pushed them aside with bulldozers and heavy equipment, damaging some spheres. Additionally, inspired by stories of hidden gold, workmen began to drill holes into the spheres and blow them open with sticks of dynamite. Several of the spheres were destroyed before authorities intervened. Some of the dynamited spheres have been reassembled and are currently on display at the National Museum of Costa Rica in San José.
The first scientific investigation of the spheres was undertaken shortly after their discovery by Doris Stone, a daughter of a United Fruit executive. These were published in 1943 in American Antiquity, attracting the attention of Samuel Kirkland Lothrop of the Peabody Museum at Harvard University. In 1948, he and his wife attempted to excavate an unrelated archaeological site in the northern region of Costa Rica. The government had just disbanded its professional army, and the resulting civil unrest threatened the security of Lothrop's team. In San José he met Doris Stone, who directed the group toward the Diquís Delta region in the southwest ("Valle de Diquís" refers to the valley of the lower Río Grande de Térraba, including the Osa Canton towns of Puerto Cortés, Palmar Norte, and Sierpe) and provided them with valuable dig sites and personal contacts. Lothrop's findings were published in Archaeology of the Diquís Delta, Costa Rica 1963.
In 2010, University of Kansas researcher John Hoopes visited the site of the Stone Spheres to evaluate their eligibility for protection as a Unesco World Heritage Site.
Stone spheres of Costa Rica