6park.comBelow is the information about the changing of the guard. 6park.comTwenty-one steps south. Face east 21 seconds. Face north 21 seconds. Twenty-one steps north. Face east 21 seconds. Face south 21 seconds. Repeat until relieved. 6park.comThis is the routine performed by the select few chosen for the honor of guarding the Tomb of the Unknown Soldier, located in Arlington National Cemetery, just outside of Washington, D.C. These Tomb Guard Sentinels, elite volunteer members of the U.S. Army's 3rd U.S. Infantry Regiment, watch the Tomb 24 hours a day, 365 days a year, rain or shine -- and have done so for almost 80 years. 6park.comThe Tomb of the Unknown Soldier was constructed in 1921, after Congress approved the burial of an unidentified U.S. soldier from World War I, with other Unknowns interred since. The Tomb has been guarded year-round continuously since 1937, when the first 24-hour guards were posted. Since April 1948, sentinels from the 3rd U.S. Infantry Regiment, also known as the "Old Guard," have been watching over the hallowed memorial. 6park.com飞向华盛顿 飞机上看湖多么的漂亮,早晨的月亮伴着我们飞行,下降华盛顿州时看见一条河。