Site clearance at Queen Victoria Street, Blackfriars, London, c 1869.

UNITED KINGDOM - APRIL 20: One of a series of photographs by Henry Flather showing the construction, undertaken between 1866 and 1870, of the Metropolitan District Railway's (MDR) underground lines between Paddington and Blackfriars via Kensington. The line laid by the MDR from the 1860s onwards was designed to provide a rail connection for travellers between London�s mainline railway terminals, situated in a ring around the city centre. It now forms part of the existing District and Circle Lines on the London Underground. The Queen Victoria Street thoroughfare was built simultaneously with the MDR and was opened in sections between October 1869 and November 1871. The line between Blackfriars and Mansion House was opened on 3 July 1871. (Photo by SSPL/Getty Images)