In Downtown -- the area within the diamond formed by Massachusetts, Louisiana, Pennsylvania, and New York avenues -- are Chinatown, Ford's Theatre, and several important museums. Thanks to an ongoing revival, the Penn Quarter section -- now somewhat vaguely called the East End -- has become arguably the most interesting part of town. Galleries and restaurants are sprouting up behind the refurbished cast-iron facades that give the neighborhood its unique look. Within Federal Triangle, a few blocks away and bordered by Pennsylvania and Constitution avenues and 15th Street NW, you can find the National Archives, which houses the original Declaration of Independence, the Constitution, and the Bill of Rights. The National Building Museum has the largest columns in the world as well as displays devoted to architecture. Other nearby museums include the National Museum of Women in the Arts, the National Portrait Gallery, and the Smithsonian American Art Museum. The Old Post Office Pavilion is also here, as is the International Spy Museum.