Last Updated: Jun 18, 2015
Costa Rica’s archaeological sites journey through history to a time of ancient civilizations, finely carved jade, precious golden jewelry, and puzzling archaeological mysteries. San Jose’s museums, particularly the Gold Museum, Jade Museum, and National Museum, offer a glance into the country’s past. The National Museum features a brief overview of the country's history, beginning with pre-Columbian artifacts, traveling through the time of the conquistadors, and gradually merging into the present.
The Gold Museum is home to the most valuable collection of pre-Columbian gold in the world: more than 2,600 gold artifacts are on exhibit, as well as a history of Costa Rica's currency and a collection of rare coins and bills. At the Jade Museum, it's not all about jade, though the beautiful green stone takes center stage. Discover carved artifacts, ceramics, precious stones, and gold miniatures from different cultural areas of Costa Rica.
Costa Rica’s Mysterious Stone Spheres
Considered one of the world’s greatest archaeological mysteries, Costa Rica’s perfectly formed stone spheres date back more than a thousand years – but no hypothesis exists to explain their purpose. The petrospheres were first discovered in the Diquis River Delta in the southern Caribbean; since then, hundreds have been uncovered throughout the country. Many archaeologists regard these as the most important sculptures of the Isthmo-Colombian era.
The stones are carved from granite and measure between three inches and eight feet in diameter; the largest specimens weigh more than 10 tons (20,000 pounds). The stone carvers were incredibly precise – deviation from a perfect sphere averages around 0.2%, astonishing for ancient artisans working with only their hands and basic tools.
The first documented sphere was unearthed in the 1930s, but the objects weren’t studied in depth until the 1940s. Unfortunately, before the spheres’ importance was fully understood, many were moved from their original location; only six remain at their original sites. A combination of factors, including the artifacts’ mass relocations, contributes to the modern-day mystery of who created the spheres and for what purpose?
A few theories have been suggested, including that the spheres were formed by nature, by aliens, or even by residents of Atlantis. What experts do agree on is the organization and technologies that would have been required to carve these masterpieces – and the highly advanced society that may have created them. Today, Costa Rica’s stone spheres are located around the country, most notably at San Jose’s National Museum and Legislative Assembly. You can also see them on Cano Island, Sierpe and Drake Bay – all on the Osa Peninsula.
Guayabo National Monument
Located about 12 miles northeast of Turrialba, Guayabo National Monument is the largest and most important archaeological site in Costa Rica. Between 400 and 1,400 AD, this pre-Columbian indigenous city was home to 1,500 to 2,000 people. Some artifacts and petroglyphs found at Guayabo date back to 1,200 BC.
The 49-acre site’s architectural complexity – a developed system of buildings, aqueducts, roads, retaining walls, and bridges – and extraordinary artistry suggest that the site was home to an advanced society and individuals of high social, political, and economic standing. Artifacts indicate that the community’s residents were highly skilled at architecture, civil engineering, and urban planning. Tombs, known as the "Tumbas de Cajon," have also been uncovered on site.
A trip to Guayabo National Monument is a trip back in time – walk though thousand-year old streets; observe ancient stone-and-wood homes; examine petroglyphs and stone statues; and explore aqueducts that once carried water from nearby streams to on-site storage tanks. Only a portion of Guayabo’s excavation is complete. The mounds or "tells" still unexplored range in size from 1.5 to 15 feet and 30 to 100 feet in diameter.
Like Costa Rica’s stone spheres, little is known about the ancient civilizations that lived at Guayabo. However, by studying other cultures in this area, it is possible to infer that a “cacique,” or chief who wielded political and spiritual power over the people of his region governed the community.
Las Mercedes Archaeological Site
Located in La Guacima, just west of Alajuela, the La Mercedes Archaeological Site features 62 acres of ancient city, including platforms, retaining walls, plazas, funeral areas, and roads. The site dates back to 1,500 BC, though its social peak began around 1,000 AD when major construction work expanded the city significantly.
Archaeologists believe that Las Mercedes once served as a political and social center, very much like Guayabo. Artifacts reveal that it may have been the center of a chiefdom, one of the most powerful political systems in pre-Columbian Costa Rica. Excavation and investigations are still ongoing.
Indian’s Rock (Piedra del Indio)
Located five miles south of San Isidro del General, Indian’s Rock has petroglyphs, or rock drawings. The site’s ancient “rock map” details the diverse geography of the Talamanca Mountain Range. The site has been declared a part of Costa Rica’s national heritage.