Archaeologists have completed an extensive rescue excavation at the site of Costa Rica’s planned Southern International Airport, uncovering new evidence of pre-Columbian life in the Diquís Delta while confirming that the development will not impact the region’s iconic monumental archaeological remains.
The investigation, led by the Ministry of Culture and Youth (MCJ) through the National Museum of Costa Rica (MNCR), recovered previously undocumented evidence of communities that lived in the Diquís Delta between AD 800 and 1500. Officials said the findings provide fresh insights into everyday life in one of the country’s most significant archaeological landscapes.
The archaeological rescue formed part of a heritage assessment launched in 2024 to identify, document and protect cultural remains before construction of the airport begins. Fieldwork was carried out between 4 March and 10 June 2026.
Researchers concentrated on 12 areas previously identified as having the greatest potential for archaeological remains. Excavations revealed residential zones containing hearths, combustion areas, pottery fragments and postholes, indicating houses built from perishable materials.
The discoveries also revealed two distinct phases of occupation, dating from approximately AD 800–1200 and AD 1300–1500. Natural sedimentation within the Diquís Delta preserved evidence from successive periods of settlement in separate soil layers, allowing archaeologists to distinguish between different phases of human activity.
Perhaps most significantly, the investigation confirmed that the airport site contains none of the monumental features for which the Diquís Delta is internationally renowned.
Archaeologists found no stone spheres, causeways, paved areas or other ceremonial structures comparable to those preserved at nearby archaeological sites including Finca 6, Grijalba and Batambal.
The findings mean the airport project can proceed without affecting these nationally important heritage assets while ensuring any archaeological materials within the construction zone have been properly documented and protected.
“Every project that transforms the country should also help us understand who we are,” said Culture and Youth Minister Jorge Rodríguez Vives.
“This archaeological rescue demonstrates that development and heritage protection are not opposing goals, but rather complementary commitments. Thanks to this research, we have a better understanding of the history of the Diquís Delta while ensuring that a strategic national project moves forward with full respect for our cultural legacy.”
Adriana Collado Chaves, Director General of the National Museum of Costa Rica, said that although no monumental structures were uncovered, the recovered artefacts would significantly expand scientific understanding of the region’s original inhabitants and their daily lives.
Laboratory analysis of the recovered materials will continue over the coming months. Once documented, the artefacts will be transferred to the José Fabio Góngora facility of the National Museum, where they will be conserved for future research.
A final technical report is expected to be submitted to Costa Rica’s National Archaeological Commission in October 2026.
The archaeological programme was undertaken through cooperation between the Ministry of Culture and Youth, the National Museum of Costa Rica, the Ministry of Public Works and Transport and the General Directorate of Civil Aviation as part of efforts to ensure the protection of archaeological heritage during construction of the future Southern International Airport.
Researchers say the discoveries will contribute to future studies of the Diquís Delta by providing new evidence of settlement patterns, domestic life and the social organisation of the pre-Columbian communities that inhabited the region. Officials added that the project demonstrates how major infrastructure developments can proceed while safeguarding Costa Rica’s rich archaeological heritage.
Sources : Museo Nacional De Costa Rica
