We visited this fort on our last morning in Vieques. It was nowhere as neat as the forts in San Juan but we had a good time. It used to be a jail and it was fun to walk around the inside and explore. It was also fun to walk around the outside and to see the views. My five-year-old son especially liked the old canons. There is also a nice little gift shop inside. You would be hard pressed to spend more than an hour here, though they do have a nice exhibit currently. It is free though they do request donations.