In honor of Memorial Day, soldiers from the U.S. Army’s 3rd U.S. Infantry regiment, known as the Old Guard, placed American flags at headstones in Arlington National Cemetery.

The annual tradition, known as “flags-in,” has been taking place at the cemetery since the 1940’s.  This year, 280,000 flags were placed at the final resting place of service members.

The Old Guard also maintains the 24-hour vigil at the Tomb of the Unknowns. Members will pick up all those flags before the cemetery reopens to the public on Tuesday.