Archaeologists uncover daily life of Costa Rica's stone sphere builders
Archaeologists in Costa Rica have completed an extensive rescue excavation at the site of the country's future Southern International Airport, uncovering valuable evidence of everyday life in the Diquís Delta while confirming that construction will not threaten the region's world-famous stone spheres.
The investigation, led by the National Museum of Costa Rica (MNCR) under the Ministry of Culture and Youth, has revealed new details about the pre-Columbian communities that lived in the delta between AD 800 and 1500, offering a rare glimpse into the domestic lives of the people associated with one of Central America's most remarkable archaeological landscapes.
Rescue excavation ahead of airport construction
The archaeological project was launched in 2024 as part of a heritage assessment before construction of the new airport.
Fieldwork took place between 4 March and 10 June 2026, with archaeologists examining twelve locations identified as having the greatest archaeological potential.
The rescue operation aimed to document and preserve cultural remains before development begins, ensuring that important archaeological evidence would not be lost.
Ancient homes and everyday life uncoveredImage Credit : Museo Nacional de Costa Rica
Excavations revealed residential areas rather than ceremonial monuments.
Researchers uncovered hearths used for cooking, combustion areas, pottery fragments and numerous postholes that once supported houses constructed from wood and other perishable materials.
These discoveries provide important evidence of daily domestic life, showing how people lived, prepared food and organised their settlements in the Diquís Delta centuries before European contact.
Two phases of settlement identified
One of the most significant findings was evidence for two separate periods of occupation.
The earliest settlement dates from approximately AD 800–1200, while a later phase belongs to AD 1300–1500.
Natural sediment deposits across the Diquís Delta preserved these occupations in separate soil layers, allowing archaeologists to distinguish between different generations of inhabitants and reconstruct changes in settlement over several centuries.
No monumental stone spheres found
Although the Diquís Delta is internationally famous for its mysterious carved stone spheres, archaeologists confirmed that none were present within the airport construction zone.
The excavation uncovered no monumental spheres, ceremonial causeways, paved plazas or other major architectural features similar to those preserved at nearby sites such as Finca 6, Grijalba and Batambal.
This finding means the airport project can move forward without disturbing Costa Rica's most significant archaeological monuments while ensuring that smaller archaeological remains have been properly recorded and protected.
Balancing development and heritage preservation
Costa Rica's Minister of Culture and Youth, Jorge Rodríguez Vives, said the project demonstrates that infrastructure development and archaeological conservation can successfully work together.
Rather than delaying development, the rescue excavation has expanded scientific knowledge while protecting the country's cultural heritage.
Officials from the National Museum added that although no monumental structures were discovered, the recovered artefacts will greatly improve understanding of the original inhabitants of the Diquís Delta and their way of life.
Research continues
Laboratory analysis of the recovered artefacts will continue over the coming months before the collection is transferred to the José Fabio Góngora conservation facility of the National Museum of Costa Rica.
Researchers will prepare a comprehensive technical report for the National Archaeological Commission, expected to be submitted in October 2026.
The discoveries are expected to contribute significantly to future research into settlement patterns, domestic activities and the social organisation of the pre-Columbian communities that inhabited the Diquís Delta.
The project also highlights how careful archaeological planning can protect cultural heritage while allowing major national infrastructure projects to proceed responsibly.
Archaeologists in Costa Rica have completed an extensive rescue excavation at the site of the country's future Southern International Airport, uncovering valuable evidence of everyday life in the Diquís Delta while confirming that construction will not threaten the region's world-famous stone spheres.
The investigation, led by the National Museum of Costa Rica (MNCR) under the Ministry of Culture and Youth, has revealed new details about the pre-Columbian communities that lived in the delta between AD 800 and 1500, offering a rare glimpse into the domestic lives of the people associated with one of Central America's most remarkable archaeological landscapes.
Rescue excavation ahead of airport construction
The archaeological project was launched in 2024 as part of a heritage assessment before construction of the new airport.
Fieldwork took place between 4 March and 10 June 2026, with archaeologists examining twelve locations identified as having the greatest archaeological potential.
The rescue operation aimed to document and preserve cultural remains before development begins, ensuring that important archaeological evidence would not be lost.
Ancient homes and everyday life uncovered
Excavations revealed residential areas rather than ceremonial monuments.
Researchers uncovered hearths used for cooking, combustion areas, pottery fragments and numerous postholes that once supported houses constructed from wood and other perishable materials.
These discoveries provide important evidence of daily domestic life, showing how people lived, prepared food and organised their settlements in the Diquís Delta centuries before European contact.
Two phases of settlement identified
One of the most significant findings was evidence for two separate periods of occupation.
The earliest settlement dates from approximately AD 800–1200, while a later phase belongs to AD 1300–1500.
Natural sediment deposits across the Diquís Delta preserved these occupations in separate soil layers, allowing archaeologists to distinguish between different generations of inhabitants and reconstruct changes in settlement over several centuries.
No monumental stone spheres found
Although the Diquís Delta is internationally famous for its mysterious carved stone spheres, archaeologists confirmed that none were present within the airport construction zone.
The excavation uncovered no monumental spheres, ceremonial causeways, paved plazas or other major architectural features similar to those preserved at nearby sites such as Finca 6, Grijalba and Batambal.
This finding means the airport project can move forward without disturbing Costa Rica's most significant archaeological monuments while ensuring that smaller archaeological remains have been properly recorded and protected.
Balancing development and heritage preservation
Costa Rica's Minister of Culture and Youth, Jorge Rodríguez Vives, said the project demonstrates that infrastructure development and archaeological conservation can successfully work together.
Rather than delaying development, the rescue excavation has expanded scientific knowledge while protecting the country's cultural heritage.
Officials from the National Museum added that although no monumental structures were discovered, the recovered artefacts will greatly improve understanding of the original inhabitants of the Diquís Delta and their way of life.
Research continues
Laboratory analysis of the recovered artefacts will continue over the coming months before the collection is transferred to the José Fabio Góngora conservation facility of the National Museum of Costa Rica.
Researchers will prepare a comprehensive technical report for the National Archaeological Commission, expected to be submitted in October 2026.
The discoveries are expected to contribute significantly to future research into settlement patterns, domestic activities and the social organisation of the pre-Columbian communities that inhabited the Diquís Delta.
The project also highlights how careful archaeological planning can protect cultural heritage while allowing major national infrastructure projects to proceed responsibly.
