Flags Across America — which has become an annual tradition for Rosslyn building landlords — marks its 18th year this year with nearly two dozen buildings draping large flags from their rooftops.

Flags Across Rosslyn started spontaneously in September 2002, on the first anniversary of the 9/11 terrorist attacks.

The Rosslyn Business Improvement District helps coordinate with landlords each year for the displays, which remain in place from for a week beginning on Sept. 11.

“Many members of the Rosslyn community were working here during the 9/11 attacks and recall firsthand the devastating impact they had on Arlington and our local community,” said Rosslyn BID president Mary-Claire Burick.

“I’m grateful to our property managers for coming together each year to fly the American flag to honor those who lost their lives on this tragic day. Even as time passes, it’s important that they not be forgotten.”

One of the best places to view the flag-draped buildings in Rosslyn is from the Iwo Jima Memorial.