The site is dedicated to the domestic terrorist bombing of the Federal Building in Oklahoma City. The site is well planned and touching (bring some tissues, just in case). If you're a National Park junkie, the stamp is located in the nearby museum, which is separate admission from the exterior park.
The exterior covers the location of the former Federal Building, honors the fallen, and preserves what could be the most touching component, The Fence. This is a chain link fence constructed to preserve the site in the aftermath of the bombing but became a public memorial where people left flowers, photos, and other objects to remember those killed in the attack.
The ends between the reflecting pond mark the time of the bombing...9:01 and 9:03...the bombing occurred at 9:02 am. The chairs represent the concentration of those killed in the attack.