Pittsburgh, PA: Home to the Pitt Panthers
Pittsburg, KS: Home to the Pitt Gorillas

Pittsburgh, PA: The second-largest city in Pennsylvania. 484 Pittsburghia: An asteroid.

Or, steel bridges vs. covered bridges.

Pittsburgh, PA: A town of ghosts. Pittsburg, CO: A ghost town.

While there is only one Pittsburgh, there are in fact many Pittsburgs.