Metro Line M1 (Budapest Metro)

Metro Line M1, also known as the Millennium Underground Railway (Hungarian: Millenniumi Földalatti Vasút) or simply földalatti ("underground"), is the oldest line of the Budapest Metro system. It is the second-oldest underground railway in the world operating with electric traction, after London's Underground.

The line runs in a northeast-southwest direction under Andrássy Avenue, from Vörösmarty Square to Mexikói út. Its construction was commissioned by Emperor Franz Joseph in 1894, primarily to alleviate traffic congestion on the avenue and provide easy access to the City Park (Városliget). It opened to the public on May 2, 1896, coinciding with the millennial celebrations marking 1,000 years of Hungarian history.

Characterized by its relatively shallow depth and closely spaced stations, Line M1 retains many of its original features, including the small yellow train cars. It is notable for its distinct architectural style, reflecting the late 19th-century design aesthetic. The stations are primarily tiled in white and green, with wooden ticket booths adding to the vintage feel.

The line consists of 11 stations: Vörösmarty tér, Deák Ferenc tér (interchange station with M2 and M3), Bajcsy-Zsilinszky út, Opera, Oktogon, Vörösmarty utca, Kodály körönd, Bajza utca, Hősök tere, Széchenyi fürdő, and Mexikói út.

In 2002, Metro Line M1, along with Andrássy Avenue and its historical environment, was designated a UNESCO World Heritage site, recognizing its significant cultural and historical importance. It continues to operate as an integral part of Budapest's public transport network, serving both locals and tourists alike.