 The mound was built about 850 CE by a regional variation of the Mississippian culture.The area's recorded history begins in the 16th century, when the first European explorers came there.Early exploration of Pensacola Bay (called "Polonza" or "Ochuse" by the Spanish) spanned decades, with members of expeditions under Pánfilo de Narváez (1528), and Hernando de Soto (1539) visiting the area.