Morning light breaks at Arlington National Cemetery, bringing moments of remembrance to these hallowed grounds. (U.S. Army Video by Jamie Mahon & Daryl Vaca / Arlington National Cemetery) | Arlington National Cemetery

For 100 years, Arlington National Cemetery’s staff have worked to maintain and preserve the Tomb of the Unknown Soldier, ensuring that future generations can pay their respects to the nameless but not forgotten soldiers who fought for our freedom. ANC Conservator Caitlin Smith explains what went into this restoration, from replacing stained and broken portions of marble to treating the Tomb’s darkening appearance from natural biofilm. ANC’s conservation team works year-round to keep the Tomb, an

The grounds of Arlington National Cemetery tell the history of our nation from the Revolutionary War through today. This video highlights our commemorative works and how we are preserving them for future generations. | Arlington National Cemetery

The Changing of the Guard Ceremony is an elaborate ritual that occurs at the Tomb of the Unknown Soldier and is one of the most popular attractions in Arlington National Cemetery. During The Changing of the Guard an impeccably uniformed relief commander conducts a detailed white-glove inspection of the incoming Sentinel's weapon, carefully checking each part of the fully functional M14 rifle once. (U.S. Army video by Sgt. George Huley and Pfc. Gabriel Silva) | 3d U.S. Infantry Regiment (The Old

CONSTANT VIGIL: The changing of the guard was performed as first snow falls at the Tomb Of The Unknown Soldier at Arlington National Cemetery. | ABC World News Tonight with David Muir