Although smaller than Turtle Mound, Castle Windy is one of the more prominent shell middens in the Indian River area. It extends some 300 feet along the shore of Mosquito Lagoon.
Castle Windy is the first Florida coastal midden for which we have radiocarbon dates. These indicate that the site developed around 1200 A.D. and continued to be used for 300 years by the same people who lived at Turtle Mound.