All Landmarks in Philadelphia

Philadelphia City Hall, located at 1 Penn Square, is the seat of government for the city of Philadelphia, in the commonwealth of Pennsylvania.At 548ft, including the statue of city founder William Penn atop it, it was the tallest habitable building in the world from 1894 to 1908. It remained the tallest in Pennsylvania until it was surpassed in 1932 by the Gulf Tower in Pittsburgh; it was the tallest in Philadelphia until the construction of One Liberty Place (1984–87) ended the informal gentlemen’s agreement that limited the height of buildings in the city. Today, it is the state’s 16th-tallest building.City Hall has been the world’s tallest masonry building since at least the 1953 collapse of the pinnacle of the Mole Antonelliana in Turin. Its weight is borne by granite and brick walls up to 22ft thick. The principal exterior materials are limestone, granite, and marble.In 2007, the building was voted #21 on the American Institute of Architects’ list of Americans’ 150 favorite U.S. structures.