William Penn's Hat
Here's a view out our apartment window:
You can see the statue of William Penn (why did I always think it was Benjamin Franklin?) on top of city hall, though the tower on which it stands is mostly blocked by a closer building. Until 1987, Philadelphia had a height restriction that no building in center city could be taller than William Penn's hat. Apparently this was an unwritten regulation; it says something about Philadelphia that it lasted until 1987. There is an interesting blog about Philadelphia called Philadelphia Reflections.