![Penn Station](https://upload.wikimedia.org/wikipedia/commons/thumb/b/b1/Pennsylvania_Station%2C_Pittsburgh%2C_2001%2C_01.jpg/800px-Pennsylvania_Station%2C_Pittsburgh%2C_2001%2C_01.jpg)
It was officially the Union Station, but there was no real union: the other important railroads (the B&O, the P&LE, the Wabash) had their own stations. Most Pittsburghers knew this as the Penn Station for the Pennsylvania Railroad, which owned it and ran most of the trains. Although this view was taken in 2001, little has changed: already the building was high-class apartments, and already the trains came into a dumpy little modern station grafted on the back. Here, on a day of patchy clouds, the afternoon sun shines a spotlight on the station’s most famous feature: the rotunda, one of Daniel Burnham’s most famous architectural achievements, so distinctive that it has its own separate listing on the National Register of Historic Places.