Special Summer Hours
The Castillo de San Marcos National Monument is extending its hours for the rest of the summer season. Until after Labor Day, the last admission to the fort will be at 6:45 p.m. instead of the usual 4:45 p.m.. Visitors will be asked to leave starting at 7:15 p.m. and the parking lot will be closed by 7:30 p.m.
The Castillo de San Marcos is open to the public from 8:45 AM to 5:15 pm every day of the year except December 25. (The ticket booth closes at 4:45 pm.) The Park grounds are closed from midnight until 5:30 am.
Visitation is lowest from the middle of September through late November.
Visitation is highest June through Labor Day, and quite high on summer and holiday weekends when an average of 3500 people visit the Castillo daily.
School group visitation is quite high February through May. High visitation can also be expected during the December holidays, and March through April.