The Fleet – London’s Underground River

If you listen carefully just above this unassuming grate you can hear the ripple and splash of flowing water. This is the sound of the River Fleet, London’s largest subterranean river. Forced underground by the city’s burgeoning populace the river still flows from its source to its mouth where it joins London’s main waterway, the Thames. Yet what lies beneath?

Below the ground there is a remarkable network of tunnels and chambers, put in to place by Victorian engineers, the final step in a process which took centuries. For over a thousand years there had been a shipping dock at the mouth of the river – its name comes from the Anglo-Saxon fleot which means a tidal inlet. Yet it was not destined to persevere as a river in its own right.

The Fleet remains tidal and these incredible pictures, taken by Flickr photographer sub-urban, show the river at its lowest level. Visitors must remain vigilant of the time as it fills to the roof in thirty minutes. Even as the time draws towards low tide the water is way above the height of a man. A short time at the upper levels and it empties out although it would be easy for the unwary traveller to be trapped and drowned on its return.

The Great Fire of London in 1666 provided that opportunity. The architect Sir Christopher Wren was afforded the chance of transforming the lower Fleet.

By 1680 this part of the river had been turned in to the New Canal. It was hailed as the Venice of England but its days were numbered from the very beginning.

It was poorly used as a canal and, despite its new clothes, it still stank to high heaven. The satirical cartoon, right, shows the new canal and the undesirables it attracted. Within a generation it was no longer fit for purpose as a canal.

The river was channelled underground in the 1730s from Holborn to Fleet Street, which still bears its name. Decades later it was filled in and arched over from Fleet Street down to the river Thames and is covered by what is now New Bridge Street.

Massive iron conduits for the river were placed along its route, including the one under St.Pancras station, above. They can still be rediscovered today by the brave and hardy souls willing to brave the depths.