Green Iguana in San Juan National Historic SiteSeveral green iguanas (Iguana iguana) can be seen basking on the historic stone walls of the San Juan National Historic Site. Their striking green and orange coloration contrasts sharply with the centuries-old masonry, highlighting the tension between natural and cultural heritage in this protected area. The iguanas appear calm, soaking in the Caribbean sun, while behind them the Atlantic Ocean frames the scene with a vivid blue horizon. This image captures both the beauty and the complexity of wildlife presence within a site of great historical and cultural value. At the same time, the photograph also represents one of the park’s greatest management challenges. Green iguanas are considered an invasive species that threatens both the structural integrity of historic fortifications and the balance of local ecosystems. Burrowing behavior can weaken foundations, while overgrazing of vegetation disrupts native plant communities. Thus, beyond its aesthetic value, the photo serves as a reminder of the ongoing conservation efforts needed to preserve San Juan’s natural and cultural treasures for future generations. Please Contact the Biologists. 
SAJU NPS 2025 
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Male Iguana iguana
Iguana Stay in the Castle 2025. 
Castillo San Cristobal - Plaza Santa Ter
This event site is located in front of the old Spanish ramp entrance to Castillo San Cristobal, it fits over 100 participants. With the amaz
Ste. Genevieve will be in totality!2024 Total EclipseWildlife at San Juan NatThe San Juan National Historic Site is not only home to centuries-old fortifications but also to a diverse range of wildlife. From migratory birds and coastal species to the challenges posed by invasive green iguanas and feral cats, the park represents a unique intersection of cultural heritage and natural ecosystems. Ongoing research and conservation efforts aim to protect both the historic structures and the biodiversity that coexists within the walls of this World Heritage Site. Wildlife ConservatioBalancing Cultural Heritage and Natural EcosystemsSan Juan National Historic Site is more than its iconic fortifications—it is also a living landscape where wildlife and history meet. Native and migratory species thrive in the park, while invasive animals such as green iguanas and free-ranging cats present ongoing management challenges. The National Park Service is committed to protecting biodiversity while preserving the historic integrity of this UNESCO World Heritage Site. Through research, monitoring, and community engagement, the park works to ensure that both cultural and natural resources are safeguarded for future generations. Documents Open for Public ReviewOther Plans and ProjectsAn archive of completed projects as well as projects without documents open for comment may be found on the PEPC website. |
Last updated: September 25, 2025