The Budapest Metro is the rapid transit system in the Hungarian capital Budapest. It is the oldest electrified underground railway system on the European continent, and the second-oldest electrically operated underground railway in the world, predated only by the 1890 City & South London Railway (now part of the London Underground). Its iconic Line 1, completed in 1896, was declared a World Heritage Site in 2002.

The first metro line was conceived as a means of carrying passengers from the city centre to the City Park without the need for surface transport on Andrássy Avenue. The Diet of Hungary approved the metro project in 1870. Construction began in 1894 and was carried out by the German firm Siemens & Halske AG.

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