The Main Line of the Pennsylvania Railroad was constructed during the nineteenth century. At the time, the Railroad owned much of the land surrounding the tracks and encouraged the development of this picturesque environment. The Philadelphia elite built sprawling estates in the area, many in addition to their homes in the city.
- Ardmore
- Bala-Cynwyd
- Bryn Mawr
- Gladwyne
- Haverford
- Merion
- Penn Valley
- Rosemont
- Villanova
- Wynnewood
- Lower Merion Township
