NS5667 : Hillhead subway station
taken 11 years ago, near to Partick, Glasgow, Scotland
The Glasgow Subway opened in 1896 and is the third oldest underground railway in the world, predated by the London and Budapest systems.
It is a very simple system consisting of fifteen stations arranged in a 10.4Km loop around the centre and west side of the city. There are two lines; the Inner Circle and the Outer Circle which run in parallel tunnels through each of the stations. The lines run entirely under ground and pass under the Clyde twice.
The four foot gauge is very uncommon and is due to the small tunnel size. The trains themselves are also small, even toy-like when compared with those on major metro systems around the world.
Here is a Link to a geograph article which provides more information about the subway.