Sentinels at the Tomb of the Unknown Soldier are part of  a unit of  military members 
who are carefully screened for this special duty

These sentinels believe that guarding the Tomb is not just an assignment, 
but the highest honor that can be afforded to a service member.

They also believe that the steady rhythmic step in rain, sleet, snow, hail, heat and cold
must be uninterrupted. To  them, the continuity of this post is the key to the honor
and respect shown to these honored dead. 

The Tomb of the Unknown Soldier is a monument in the Arlington National cemetery, 
dedicated to the services of an unidentified soldier, Marine, airman or sailor killed in any war.

This service member cannot be returned to his home, his friends and loved ones will not know for certain how or when he died, he cannot be placed to rest in a site of his own choosing. 

He will forever remain as a soldier who not only gave up his life for his country,
 but his very identity as well.

He now stands for the purest ideals of courage, valor, and sacrifice
 and serves as a noble and selfless representation of the duty to one's country.

It was amazing to see the changing of the guard ritual the time I visited Washington, DC.
The guard is changed every hour on the hour from Oct. 1 to March 31.
 And every 30 minutes from Apr. 1 through Sept. 30.
These pictures are from some years ago, but I will never forget how cool it was to witness it!