Oral tradition says it was located on the northern shore of Lake Concord, essentially in the Home Depot parking lot. I spoke about the "fort" extensively in this post: Casselberry's original settlement, Concord. Some legends state that it was built...
Seminole Wars
Was there really a Fort Concord?
Visit to Lake Harney’s Mansfield Island in 1891
In January 1891, photojournalist Clarence Bloomfield Moore traveled down the St. Johns River with a small crew. It had become an annual tradition since he first journeyed deep into the Florida wilderness in 1879. Moore was a Harvard-educated archeologist from...