NPS areas in and around the nation's capital will host or assist in special activities during the upcoming Memorial Day weekend, including an unusual concert and opportunity to view the city from a unique location.

The Big Day on the National Mall has come and gone, thankfully without major incidents. The National Park Service has compiled a few behind-the-scenes facts and figures, but contrary to published reports, there won't be an official estimate of the crowd from that agency.

With crowds predicted to number three-four million or more, the National Park Service is scrambling to accommodate the largest event in its history.