Where London is situated today was once the floodplains of the river Thames, surrounded by gently rolling hills and valleys carved by the river itself and its innumerable tributaries. London originally began on the Thames' north bank and for many centuries London Bridge was the only bridge over the Thames close to the city. But as the city grew, the marshlands and streams feeding the Thames began to get in the way of growth and were gradually buried under streets and houses.

“Today, in many parts of the city you could be standing within inches of one of its lost rivers and not even realise it,” wrote Andy Dangerfield on BBC.

A plaque in Gipsy Road, West Norwood, reads: “The Hidden River Effra is Beneath Your Feet”. Photo credit: diamond geezer/Flickr

For instance, there is a river running directly under Buckingham Palace—the Tyburn. Once reputed for salmon fishing, Tyburn is now a sewer. The Walbrook, which was once an important river of Roman London bringing fresh water to the city, now flows quietly through a tunnel under the vaults of the Bank of England. It is thought that the river was named because it ran through or under the London Wall.

The most legendary of London’s subterranean rivers is Fleet. It was once a broad tidal basin, a hundred feet wide when it reached the Thames, and its waters was supposed to have healing properties. But like many of London's other rivers it became increasingly filthy as the city's population grew. In fact, the Fleet's reputation for slum dwellings, crime and disease was such that it inspired Charles Dickens to base Fagin's Den in Oliver Twist on the area it flowed through. The Fleet was such foul-smelling that the satirical 18th century poet Alexander Pope penned these lines in its dubious honor:

To where Fleet-ditch with disemboguing streams

Rolls the large tribute of dead dogs to Thames

The king of dykes! than whom no sluice of mud

With deeper sable blots the silver flood.

Inside the sewers of River Fleet. Photo credit: Jon Doe/Flickr

Following the Great Fire of London in 1666, Christopher Wren's plan to redevelop the river into Venetian-style canals was quickly abandoned. Instead, the river was buried under a culvert. The final section of the river disappeared underground in the 1870s following the Great Stink of 1858 that saw the construction of Joseph Bazalgette's incredibly visionary sewer system that’s still functioning to this day.

Today, if you stand at Ray Street, Clerkenwell, in front of The Coach pub, just off Farringdon Road, you can hear the soft murmur of the waters of Fleet flowing through the sewer. The Fleet can also be heard through a grid in the center of Charterhouse Street, where it joins Farringdon Road, and if you exit through Thameswalk of Blackfriars station, you can see the Fleet gushing into the Thames under Blackfriars bridge.

The mouth of River Fleet appearing as a drainage outlet in the embankment wall beneath Blackfriars Bridge. Photo credit: diamond geezer/Flickr

The Walbrook, which once flowed openly through the center of Roman London and was used for transport, was paved over in the 15th and 16th centuries. The Romans had a temple and port in its banks. The temple was later found during rebuilding work after World War I. Archaeologists also discovered scores of human skulls in the bed of the river which are thought to be the heads of Romans executed by Boudicca’s rebelling army.

A total of twenty one rivers were forced underground by the burgeoning city, but their impact on London's landscape remains. The Oval cricket ground was built into a bend in the River Effra, and the stadium’s raised banks were built with earth excavated during the enclosing of the Effra.

“Mysteriously steep roads, such as Pentonville Rise, make sense when seen as the sides of the Fleet Valley. The sharp dip as Piccadilly passes Green Park shows us where the Tyburn once crossed the road,” wrote Tom Bolton, who has authored a book on London's underground rivers.

The names of many streets and neighborhoods also reflect London’s hidden and forgotten hydrology. Fleet Street is named after the River Fleet and its eastern end is at what was historically the crossing over the river known as Fleet Bridge. The Bridewell Palace located on the western bank of the Fleet River once had a long gallery that led to the river frontage and a watergate. The palace was demolished in the 19th century and this area is now known as 'Bridewell Court'. A small lane near this site was named Watergate.

"It's a shame so many rivers were buried - today they would enhance the landscape," says Paul Talling, who organizes walking tours along some of the lost rivers' paths. If you are interested in learning more about these rivers, visit Talling’s fantastic site.

Map of London’s lost rivers. Photo credit: Sandra Crisp

Corporation of London workmen repairing the Fleet sewer, south of Fleet street in 1854.

Construction work in 1845 to deepen the sewer carrying the Fleet down Fleet Street.

The outlet of River Effra. Photo credit: Steve Harris/Flickr

The outlet of River Walbrook. Photo credit: Matt Brown/Flickr

Source of the Tyburn. Photo credit: Kevan/Flickr