Área de Conservación Guanacaste (ACG) is a 169,000-hectare protected area in northwest Costa Rica contains 65% of the country's biodiversity and almost 3% of the world's terrestrial biodiversity. ACG is an almost 40-year-old pilot project for restoration and conservation of tropical biodiversity into perpetuity, through innovation, collaboration, science, and home-grown understanding of the natural world. As such, ACG programs and projects with GDFCF are highly regarded across the global tropical conservation and science community.

Área de Conservación Guanacaste, a UNESCO world heritage site, has been in a public-private collaboration with the non-profit Guanacaste Dry Forest Conservation Fund for almost 40 years. Together, ACG and GDFCF have pioneered a concept of protected area management that is public-private, locally and government-determined, and based on mutually beneficial relationships with its neighbors.

Since 1985, we have enlarged the protected area of ACG sixteen fold to its current size of 169,000 hectares; raised over $100 million over 30 years to support land acquisition, while expanding the reach of the protected area beyond dry forest to the marine sector and rain and cloud forest; developed the unique system of employment and training of local parataxonomists, who are local Costa Ricans, most of whom have little to any formal education beyond sixth grade, trained for careers in biodiversity management; oversee a bioinventory project of both the terrestrial and marine ecosystems of ACG through the pioneering use of DNA barcoding, as well as a project, BioAlfa, which seeks to determine all the multicellular species in Costa Rica; oversee the restoration of thousands of acres of tropical dry forest, as well as mid-elevation Caribbean rain forest; support research on migratory birds, sea turtles, and jaguars; and, support an environmental education program for thousands of school children living in the communities surrounding ACG.

ACG's topography, size, and ecosystem variability are designed to protect its biodiversity from humanity while being used in a non-damaging way, and — to the extent possible — protect it from the ravages of climate change by making it as large and resilient as possible. Still, the impact of climate change is being felt throughout the protected area and it is imperative that we accelerate our bioinventory so we can understand what is here before it is gone. We have already seen an alarming decrease in the abundance and diversity of insects, and we fear there are many that are winking out before even being discovered or described. We recognize that we can never return this landscape to its original state, because of climate change, but we are determined to "be kind to the survivors" and ensure the area is large enough to ensure the survival of what biodiversity remains into perpetuity. Our solution is to work together to preserve the biodiversity of ACG through biodevelopment, world class science, bioliteracy education for children, protection of our extraordinary marine and coastal resources, and targeted land acquisition from willing sellers. Large, complex and socially-integrated protected areas do not take care of themselves and public budgets are often not enough to take care of the need. GDFCF adds critical capacity to ACG in numerous areas to ensure the mission of biodiversity survival is realized.