 Originally the line was planned to run into the centre of Buenos Aires through a long tunnel. But when the tunnel was finally built in 1930, it ended up as the Line B. The access ramp still exists and is in use today, but for maintenance and storage purposes rather than for passenger services. The Urquiza Line itself opened in 1948, so suburban passengers travelling on the Underground's Line B have to transfer to the Urquiza Line at Federico Lacroze station, named after its builder, about 6 km (3.7 mi) from the city centre.
