"ignored the entrance to the Underground"

Piccadilly Circus Underground Station
Creative Commons Attribution Share AlikePiccadilly Circus Underground Station - Credit: Leonardo Cassarani
The London Underground is a rapid transit system serving a large part of Greater London and neighbouring areas of Essex, Hertfordshire and Buckinghamshire in the UK.
London Underground Map Zone 1
Creative Commons Attribution Share AlikeLondon Underground Map Zone 1 - Credit: ed g2s
With its first section opening in 1863, it was the first underground railway system in the world. In 1890 it became the first to operate electric trains. Despite the name, about 55% of the network is above ground. It is usually referred to officially as 'the Underground' and colloquially as the Tube.