Fort Jefferson, Gulf of Mexico

 

Fort Jefferson in the Gulf of Mexico. (2005, public domain)

 

Dry Tortugas Fort Jefferson
A more recent photo of Dry Tortugas Fort Jefferson. (CC BY 2.0 ©2012 Michael
Worthington)

 

The moat
The moat around Fort
Jefferson. (CC BY-SA 2.0 ©2010
Matt Kieffer)