Millbourne, Pennsylvania
With fewer than 1,200 residents living in less than 1/10th of a square mile, the tiny Delaware County borough just outside the Philadelphia border is the most densely populated incorporated municipality in Pennsylvanina.
With fewer than 1,200 residents living in less than 1/10th of a square mile, the tiny Delaware County borough just outside the Philadelphia border is the most densely populated incorporated municipality in Pennsylvanina.
