Security Fence and Screening Facilities: Independence National Historical Park Philadelphia, Pennsylvania: Environmental Assessment [open pdf - 807KB]
"Independence National Historical Park is federal parkland under the jurisdiction of and maintained by the National Park Service (NPS). Spanning over 55 acres on 20 city blocks within the City of Philadelphia, the park preserves and interprets resources associated with the establishment of the United States of America, including: the site of the meetings of the first and second Continental Congresses and the site at which the Declaration of Independence, the Articles of Confederation, and the Constitution of the United States of America were debated and signed. […]. In response to Homeland Security Presidential Directive -- 7, the NPS must improve the current temporary security fence and screening facilities at the Liberty Bell Center and Independence Square within Independence National Historical Park. The purpose of taking action at this time is to allow Independence National Historical Park to protect Independence Hall and the Liberty Bell, national icons. The objectives include: Improvement of Security -- Due to the high visibility and importance of Independence Square, the Liberty Bell Center, and the national icons within these properties and because of increased national security concerns, the park requires protection against acts of crime and terrorism. Required security elements include (1) a permanent facility to screen individuals entering the Liberty Bell Center; (2) the use of the Old City Hall for screening individuals at the Independence Square Complex; and (3) security fencing located around the perimeter of the bell chamber at the Liberty Bell Center and the northern portion of Independence Square."
National Parks Service: http://www.nps.gov/