1. This gallery of what some of our cities looked like 100 years ago will make you stop and think about time — how it passes and how, while it passes, urban landscapes change. A lot. Who knew? Above, our fair city of Philadelphia. View in High-Res

    This gallery of what some of our cities looked like 100 years ago will make you stop and think about time — how it passes and how, while it passes, urban landscapes change. A lot. Who knew? Above, our fair city of Philadelphia.

  2. Time warp

    Philly