Historic Building Plan of the Day
Castillo de San Marcos
The star fort and its moat and outworks were built to protect Spanish territory in Florida from attacks by the English. Castillo de San Marcos is the oldest masonry fort in the continental U.S.
- Time to build: 1672–1695, per HABS record
Historic American Buildings Survey, Library of Congress, Prints & Photographs Division. Library of Congress item. Full drawing: Elevation at loc.gov. No known restrictions on images made by the U.S. Government; images copied from other sources may be restricted.