Philadelphia City Hall is the seat of government for the city of Philadelphia, Pennsylvania. At 167 m (548 ft), including the statue, it is the world’s second-tallest masonry building, only 1.6 feet (0.49 m) shorter than Mole Antonelliana in Turin. The weight of the building is borne by granite and brick walls up to 22 feet (6.7 m) thick, rather than steel; the principal exterior materials are limestone, granite, and marble.
It was the tallest habitable building (although surpassed by monuments) in the world from 1901 to 1908 and the tallest in Pennsylvania until 1932 when surpassed by the Gulf Tower. It remained the tallest building in Philadelphia until the construction of One Liberty Place (1984–1987) broke the informal “gentlemen’s agreement” that limited the height of tall buildings in the city; it currently is the 15th-tallest building in Pennsylvania.
With close to 700 rooms, City Hall is the largest municipal building in the United States and one of the largest in the World. The building houses three branches of government, the Executive (Mayor’s Office), the Legislative (City Council), and the Judicial Branch’s Civil Courts (Court of Common Pleas).
The building is topped by an 11.3-m (37 ft), 27-ton bronze statue of city founder William Penn, one of 250 sculptures created by Alexander Milne Calder that adorn the building inside and out. The statue is the tallest atop any building in the world.- Wikipedia