The prehistoric temple mound, located on the museum grounds, represents one of the most outstanding artifacts left by the early inhabitants of this community. Built as a ceremonial and political center by the Mound Builder Culture between 800-1400AD, this mound is thought to be the largest on salt water and possibly the largest prehistoric earthwork on the Gulf Coast. The Fort Walton Temple Mound stands 12 feet tall and measures 223 feet across its base. An estimated 200,000 basket loads of earth were used to create this earthen structure.
In 1964 the Temple Mound was designated a National Historic Landmark and is listed on the National Historic Register. The original temple sat atop the mound and was used as the residence of the leader, a temple for religious ceremonies, and a place to direct the activities of the village. It was and still is a sacred burial ground.
After the Mound Builders abandoned the mound in the 1500s, the mound lay dormant; its history quiet as European explorers moved through the area. Interest in the mound would not rekindle until the Civil War in 1861 when Confederate soldiers of the Walton Guard encamped here to guard the waterway known as "The Narrows". The soldiers displayed curiosity taken