Wien Hauptbahnhof U-Bahn, Wien (Vienna), Austria, 2013

Vienna is actually a city of over 1.7 million people, so it is large enough to support a subway, or untergrundbahn. The Vienna untergrundbahn is unimaginatively called the U-Bahn. This is the Hauptbahnhof station. All of the current U-Bahn lines were constructed in 1976, except for lines U4 and U6, which were built in 1898. This is line U1, with this part of the station being opened in 1978, so it's a little bit surprising how dark and dank it looks. It's perfectly functional, though, and not vandalized nor abnormally dirty.