Old Fort Park in New Smyrna Beach is a fascinating and mysterious site. Its most striking feature is a massive, 40-by-80-foot foundation made of coquina (shell stone), which many people assume is the remains of an 18th-century Spanish fort. But archaeologists aren’t convinced — there’s no entrance or other typical fort features. Instead, some think it was Dr. Andrew Turnbull’s unfinished mansion, or perhaps a large storehouse, church, or even a shipbuilding site connected to his Smyrnea colony.