The Vienna (Wien) subway opened in 1898, part of which was a private railway
for the Kaiser. It ran old steam trains, much in the fashion of the
London tube. It was electrified in 1925, but much of the system was
destroyed in the second world war. Technically, wien's U-Bahn opened for business in 1976, however, when actual tunnels were dug and sections of the streetcar system and the Kaiser's private railway were integrated into the new subway.
The system currently is 74.6 km long, with 5 lines and 101 stations. All lines
are heavy metro except for line U6, which is light rail. Tram lines 6, 62,
18 and 65 and the Wiener Lokalbahn, a interurban-style light rail line also known as the Badner Bahn, all share
a 1.2 km tram tunnel. Vienna's airport also includes a subway station which is served by a local commuter train.