Friends of the Rail Forum

Vatican City has a railway line. It is a standard gauge spur 860 metres long, officially opened on 2nd October 1934, running from a junction on the Rome-Viterbo line at San Pietro Station, with its own 143 metre long eight-arch viaduct ending up in the pope's private garden through a bridge fitted with two 35 ton sliding iron doors. Apparently it is very rarely used, but there was a steam special in May 2011.

Source: The Railway Magazine, June 2011, p 28, in an article entitled The world's smallest state railway

See also Vatican train station and railway line opens to the public (BBC) for some video and a photo here