This was the world's first underground passenger railway which opened from Paddington to Farringdon via Baker Street Station on 10th January 1863.
IanVisits has reproduced an Illustrated London News report on the construction of this line. Our picture is a detail off the Company's 1912 HQ in Allsop Place NW1.
Londonist have published a great piece on this historic infrastructure - they've even nailed the first piece of rude underground graffiti.
The line is now the Metropolitan Line, for which Londonist have a good succinct history.
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