London Underground: World's first metro system, started in 1863

Paris Métro: Iconic Parisian transit system began in 1900

New York City Subway: Launched in 1904, a bustling urban network

Boston Subway: America’s first, started operations in 1897

Berlin U-Bahn: Historic system, first trains in 1902

Moscow Metro: Opened in 1935, known for ornate stations

Tokyo Metro: Started in 1927, a major global hub

Madrid Metro: Began in 1919, extensive network across city

Vienna U-Bahn: Launched in 1978, renowned for efficiency

Shanghai Metro: Oldest line from 1993, rapidly expanding network

Hong Kong MTR: Started in 1979, critical to city transport

São Paulo Metro: Began in 1974, a vital Brazilian transit system