Roughly 80 feet (24m) wide and 20 feet (6m) tall, the Spruce Bluff Mound is a remnant of the Pre-Columbian Ais Culture, who lived along the Indian River Lagoon between Cape Canaveral and the St. Lucie Inlet. The mound has been to dated to around 300–100 BC and is perhaps the largest surviving example of an Ais mound left standing today.