Memorial Amphitheater, just w. of jct. Memorial and Wilson drs. in Arlington National Cemetery, is an elliptical white marble structure honoring those who have defended the nation. It seats approximately 5,000 people. The Memorial Display Room, between the amphitheater and the Tomb of the Unknown Soldier, contains information about the amphitheater's construction as well as details about the unknown American service members interred at the tomb and the sentinels who guard the monument.