Picture William Penn's original city plan meeting the largest masonry building in the United States, once the tallest habitable building in the world. Philadelphia City Hall sits at the intersection of Broad and Market Streets, the crossing point of Penn's two main boulevards, exactly as Penn planned in 1682. The building took thirty years to construct, from 1871 to 1901, and its French Second Empire design — white marble over a granite base, 700 rooms, nine acres of floor space — was so grandiose that it became an object of ridicule before it was finished.
At 548 feet to the top of the statue of William Penn on the tower, it was the tallest habitable structure in the world until 1908. For most of the twentieth century, a gentlemen's agreement kept no building in Philadelphia taller than Penn's hat, at around 491 feet. In 1987 that agreement was broken when One Liberty Place was built, and today the skyline has multiple towers taller than City Hall.
The tower observation deck is open to visitors; take the elevator to the top and look at Penn's bronze face and the city stretching in all four directions below.