Caddo Mounds State Historic Site is 6 mi. w. to 1649 SR 21W. The southwesternmost ceremonial center of the Mound Builder culture, this settlement was occupied by Caddo Indians approximately A.D. 800-1300. A museum features artifacts from the site. An interpretive trail guides visitors to the burial and temple mounds; another trail leads to a segment of the historic El Camino Real.