The Castillo de San Marcos (CASA) is a coastal fortification in St. Augustine, Florida that is the nation’s only extant 17th century military construction and the oldest masonry fortress in the United States. The site is among the most vulnerable of NPS units to the effects of weathering, erosion, and climate, and it is a highly visited national park tourism location. The fort site is in the low-lying, vulnerable coastal zone in the city of St. Augustine (est. 1565), built to protect Spain’s claim to La Florida. The Castillo has a significant economic, cultural, and historical impact at state, national, and international levels.

The Castillo, made of fragile coquina, is at a critical juncture. Once the fort’s outer plasters are diminished, the soft structure is exposed, making it susceptible to weathering and surface deterioration. The rising sea levels and increased storm surge in St. Augustine, along with threats from hurricanes and other weather events, have accelerated the process of structural fractures, material breakdown, salt intrusion, and foundational slumping. The time to act is now, and the USF CDHGI, along with our NPS partners, have taken steps to ensure baseline and necessary digital documentation of the fort in its entirety has been completed. Emergent analyses, interpretive, and educational materials continue to develop and evolve from this critical undertaking.

In a partnership with the National Park Service and the Southeast Archeological Center (NPS SEAC), the Center for Digital Heritage and Geospatial Information (USF CDHGI – Collins and Doering PI) undertook a comprehensive preservation effort. We 3D surveyed and documented the entirety of the fort and environs, including the seawall and City Gate. We also create preservation and management planning tools, education and outreach materials, and baseline monitoring and conservation information from this survey to preserve this historic site for future generations.

The USF CDHGI team used a suite of reality capture methods, including 3D laser scanning, imaging, drone aerial survey, and geospatial analysis. From a close-range scale, we documented fragile carvings and wall surface details and artifacts, and at a broader scale, our work produced a digital twin of site features, landscapes, and structures at the fort. These data are being used to develop educational and interpretation tools for use on-site and off-site, as well as virtual and online visualization and sharing, including a highly viewed annotated virtual tour of the entire park and environs.

View our GIS interactive map here.

View our 3D models here.