Arlington National Cemetery's Tomb of the Unknowns, also known as the Tomb of the Unknown Soldier, has never officially been named. Which is appropriate, given its theme.

On March 4, 1921, Congress approved the burial of an unidentified American soldier from World War I, known as "The Great War" at the time, in the plaza of the new Memorial Amphitheater. On Memorial Day that year, four unknowns were exhumed from American military cemeteries in France. Veteran Edward F. Younger selected one of them by placing a spray of white roses on the third casket.

The chosen unknown soldier was transported to the United States on the USS Olympia. On Nov. 11, 1921, President Warren G. Harding officiated the interment ceremony at the Memorial Amphitheater.

The white marble sarcophagus has a flat-faced form, neo-classic columns, three Greek figures representing peace, victory and valor, and six wreaths, representing the six major campaigns of World War I.

Inscribed on the back of the tomb are the words:

Here rests in honored glory an American soldier known but to God

West of the World War I Unknown are the crypts of unknowns from World War II and Korea, all marked with white marble slabs flush with the plaza. The crypt for the Vietnam Unknown remains vacant after the body was exhumed for DNA testing and identified in the 1990s.

The tomb is guarded 24 hours a day, 365 days a year, and in all weather conditions by sentinels from the Army's 3rd Infantry Regiment (aka "The Old Guard"), headquartered at Fort Myer, Va.