Photo taken on Aug. 23, 2011 shows the Pentagon Memorial of the 9/11 attack on Pentagon in Washington D.C., the United States. The U.S. Department of Defense Press Office hosted the media day at the Pentagon Memorial prior to the commemoration event of the 10th anniversary of 9/11. Opened on Sept. 11, 2008, the Pentagon Memorial is the first dedicated national commemorative to honor those killed during the 2001 terrorist attacks. [Xinhua/Riccardo Savi]