Researchers from the University of Michigan and Tulane University have been excavating the site near the city of Morganton in western North Carolina, nearly 300 miles from the Atlantic Coast.
Spanish explorers built Fort San Juan in the foothills of the Appalachian Mountains in 1567, nearly 20 years before Sir Walter Raleigh's "lost colony" at Roanoke and 40 years before the Jamestown settlement established England's presence in the region, a UM release said Tuesday.
"Fort San Juan and six others that together stretched from coastal South Carolina into eastern Tennessee were occupied for less than 18 months before the Native Americans destroyed them, killing all but one of the Spanish soldiers who manned the garrisons," UM archaeologist Robin Beck said.
The Berry site, named in honor of landowners James and the late Pat Berry, is located along a tributary of the Catawba River.
It was the location of the Native American town of Joara, part of the mound-building Mississippian culture that flourished in the southeastern U.S. between A.D. 800 and 1500.
In 2004 the researchers began excavating several of the houses occupied by Spanish soldiers at Joara, but the remains of the fort eluded discovery until last month.
"We have known for more than a decade where the Spanish soldiers were living," Tulane archaeologist Christopher Rodning said. "This summer we were trying to learn more about the Mississippian mound at Berry, one that was built by the people of Joara, and instead we discovered part of the fort. For all of us, it was an incredible moment."