Headquarters of the US Army Field Artillery. The Old Post Area was established in 1869 to control local Indian tribes; the grave of Geronimo and graves of other famous American Indians, on Chiefs' Knoll in the Old Post Cemetery, can be visited daily during daylight hours. The Old Stone Corral contains frontier relics including military and pioneer horse-drawn vehicles, Indian tepees and replicas of a trader's store and blacksmith shop. The Geronimo Guardhouse, where warriors were imprisoned, now houses exhibits commemorating Indian Territory days. Cannon Walk, which links the guardhouse to other exhibit halls, displays various weapons from battlefields around the world, including the 280-millimeter gun that fired the first atomic artillery round.

Open daily 8:30am-4:30pm; admission free. Closed Dec. 25-26 & Jan. 1-2. Located 5 miles north of Lawton on Hwy 62/77/281 to Key Gate Entrance.