Experts from Costa Rica and Mexico will restore the biggest stone sphere in Costa Rica

The Archeological site “El silencio” is Wolrd Heritage patrimony. The sphere is 2.66 meters in diamters and weights 24 tons. For years it has been suferin alterations for both human and natural causes

The works to restore the stone is a milestone in the history of conservation and restoration of pre columbian artifacts. “El Silencio” archeological site is located in Palmar Sur in Osa.

Since the 15th of april. A team of professional archeologists from Mexico and Costa Rica. Had been working in a bilateral cooperation. Procuring to better understand the spheres. El Silencio is the biggest Sculpture Monument in the country.

This season the team of specialist had been cleaning the area. Searching for little fragments of rock that might had been lost. And reintegrating those fragments to the stone. Some of the fragments had been conserved by the National Museum during the last years.


It was thanks to the labour of the people of the National Museum. During more than a decade and the continues excavation projects. What have made possible for the fragments to return to their original place


Dra. Isabel Medina-González, de la Escuela Nacional de Conservación, Restauración y Museografía del Instituto Nacional de Antropologías e Historia de México (ENCRyM-INAH), quien coordina la misión

In addition to this there are works in progress preserve the sphere and avoid future degradation.

We had apply layers and techniques to prevent damage. With cal and sand. With this effort we are sure the sphere appearance is going to change. Is not going to look as when it was new. But our goal is to preserve the values, autenticity and integrity that made the sphere significant and relevant. As a pre columbian legacy that shows the legacy and the past of time during hundreds of years..


Dra. Medina-González.

In addition to the sphere. In the site exists a stone formation. Made of river stones. With an extention of 12 meters large and 1 to 2 meters wide. Orientadeted Northeast to Southeast.

For the 2019 season. 2 areas were excavated. Procuring to document and diagnost the area. Because of this methodology the area was evaluated and the conservation works began. To replace missing parts of the monuments.

The intervation were made with compatible materials. Used by the precolumbian cultures of the Southeast of Costa Rica. The areas treated are well differentiated so the authenticity and importance is left untouched.

A systematic and multidisciplinary work

To ge to the shere of El Silencio. Implied and systematic and multidisciplinary effort. Than this 2019 sums three years of field and laboratory labor. A continues register of fluctuations of temperature and humidity was develop. Plus photographic documentation of the alteration, textures and hardness, salt, and water absortion. Javier Fallas said.

According to Medina- González. It was thanks to this diagnosis of the archaeological findings. And the impact of the environment over the sphere. Carry by different institutions. That a well informed decisions was taken. To interveen the sphere.

The work of the INAH and the National Meseum has also develop the acquisition of knowledge. In regards of archaeological conservation. So when the season of Medina-Gonzalez end. Javier Fallas, Alfredo Duncan, and Alonso Silva of the National Museum. Stay applying the develop techniques to the site.

To get to this stayed. Several public and private institutions had add a hand to the effort. Places as Laboratorio Nacional de Nanotecnología (LANOTEC-CENAT), Laboratorio Nacional de Materiales y Modelos Estructurales (Lanamme de la UCR), la empresa SG, el Instituto Nacional de Investigaciones Nucleares (ININ) y el Instituto de Investigaciones Estéticas de la Universidad Nacional Autónoma de México (IIE-UNAM). the first four been Costa Rican and the last two Mexican.

At the beginin of 2019 LANOTEC of the National Center of Technology (CENAT-CONARE) and the company SG. Did a 3D mapping of the sphere. Trough laser scans and photo metrics. This created a high detail recreation of the monument.

El Silencio

El Silencio together Grijalba 2, Finca 6 and Batambal. Is one of the four sites declared World Heritage by UNESCO in 2014. The site is 20 Hectares. And at the back the biggest precolumbian sphere till date can be found. Sculpted in a rock call Gabrodeorita.

The sphere is 2.66 meters in diameter and weights around 24 tons. And has endured climate and man made fires.

The conservation efforts are thanks to the ININ, el IIE-UNAM, ENCRyM-INAH (México), the UCR, LANOTEC-CENAT y Grupo SG.