Turtle Mound, a 35-foot-high shell mound and the tallest in Florida, was created between AD 800 and 1400 as an Indian midden composed mostly of oyster shells. Throughout history it served as an important home and landmark for Timucuan Indians, Spanish explorers, and early Floridians, and it preserves a vital archaeological and environmental record of the past. The mound is experiencing extensive shoreline erosion and loss of artifacts from natural and human disturbances, including boat wakes and recreational use, freezes and storms, high-water events and changes in sea level, and non-native plants and animals. Efforts in adjacent waters are creating a living shoreline of native species, with stabilizing shells for eastern oysters, marsh grass to disperse wave energy and bind sediments, and red and black mangroves to establish roots that stabilize sediments and runoff.