The Ancient Dunes Nature Trail loops through a shaded maritime hammock through the ancient dunes. Visitors can also explore up to four miles (one way) of pristine beach, along with the coquina quarries located at the park entrance. This archaeological site dates from the 1700s, when the Castillo de San Marcos was first built. The quarries were continuously used until the turn of the 20th century. This is a protected historic site and on the National Register of Historic Places.