The Metropolitan Railway, the world's oldest underground railway, opens between Paddington and Farringdon, marking the beginning of the London Underground.

The Metropolitan Railway was a passenger and goods railway that served London from 1863 to 1933, its main line heading north-west from the capital's financial heart in the City to what were to become the Middlesex suburbs. Its first line connected the main-line railway termini at Paddington, Euston, and King's Cross to the City. The first section was built beneath the New Road using cut-and-cover between Paddington and King's Cross and in tunnel and cuttings beside Farringdon Road from King's Cross to near Smithfield, near the City. It opened to the public on 10 January 1863 with gas-lit wooden carriages hauled by steam locomotives, the world's first passenger-carrying designated underground railway.

Paddington is a London Underground station in Paddington, London. It is located adjacent to the north side of Paddington mainline station and has entrances from within the mainline station and from Paddington Basin. The station is on the Circle and Hammersmith & City lines between Royal Oak and Edgware Road stations and is in London Fare Zone 1.

Farringdon is an interchange station located in Clerkenwell, London, England, in the London Borough of Islington, just outside the boundary of the City of London for London Underground, Elizabeth line and National Rail services.

The London Underground is a rapid transit system serving Greater London and some parts of the adjacent home counties of Buckinghamshire, Essex and Hertfordshire in England.