Take one look at the skyline and it's no wonder Pittsburgh's been nicknamed "The City of Bridges." With more than 440 bridges, 150 skyscrapers, and a countless number of steel behemoths, Pittsburgh is Pennsylvania's second largest city (behind Philadelphia) with a population of nearly 334,000. The city is composed of nine districts, each represented by a council member, while the mayor rounds out the executive side. Its annual budget goes toward enhancements to health care and retirement as well as hiring police and fire prevention personnel; most of its revenue comes from real estate taxes. Pittsburgh was founded in 1758.