You can visit Fort San Felipe for $2 per person; it is accessible daily. Admission includes the use of an audio guide with English commentary about the history of the fort. Restrooms are available ...

Fort San Felipe is right in the center of the town ... which are fascinating to explore. You'll also find fossil formations here that you're unlikely to find anywhere else. I've written before ...

El Morro, which sits within the San Juan National Historic ... comfortable walking shoes, as the fort is quite large: it can take up to three hours to explore the whole place on foot.