Milne Calder, the grandfather of artist Alexander Calder, created over 250 sculptures which adorn the building. You'd never know this stuff could be on a ceiling in the middle of Philadelphia. City Hall, decorated with external clocks to inform the citizenry, contains a large, prominent, broken clock in the City Council chamber. The tour guide maintains the City Council Chamber is larger than the House of Commons. Tours leave every 15 minutes.
Tours are free.
Steer your car toward that big guy standing in the middle of the city on top of City Hall. Park underground nearby and take the free tour of this unusual building. It's hard to get kids there during the week. Stay open later one night a week so non-custodial parents can take kids on the tower tour. Fort Mifflin I first noticed this Revolutionary Fort when taking off from Philadelphia Airport.