Back to London's premier lost river, now on the descent from King's Cross to Clerkenwell along the approximate line of the Camden/Islington boundary. It's no coincidence that the Fleet once marked the divide, although previously the boroughs were St Pancras on one side and Finsbury on the other. There are very clear contours in the area, the roads dipping down from Bloomsbury and more steeply on the opposite flank, although the precise level of the valley has been disguised somewhat by subsequent development. In 1768 there are accounts of the river flooding four feet deep round here, carrying off three cattle and several pigs, whereas what's being swept away today is the old streetscape. Rows of fine Georgian terraces survive at the top of Pakenham Street, but look down Phoenix Place and pretty much nothing of what I saw 20 years ago remains.
The site to the left was once Coldbath Fields, source of yet another medicinal spring, and in 1794 a conveniently large open space on the edge of town on which to build a massive prison. The delightfully-named Middlesex House of Correction was originally used to house those waiting to be tried by magistrates, but later gained a fearsome reputation as a strict men-only institution with an enforced regime of silence. The governor was eventually dismissed following an inquiry and the prison closed in 1885. Enter the Post Office who purchased the site as somewhere to sort their parcels, a growing trade, creating what would soon be one of the largest sorting offices in the world. The upper section once used for parking hundreds of red vans was sold off a few years ago, inevitably for housing, as was the scrubby car park across the road. The resultant estate is called Postmark and has crammed in 681 luxury flats starting at £990,000, the sole enticing feature being the row of pillar-box-shaped vents along the central raised garden.
A more attractive local presence is the Postal Museum which opened at the top of Phoenix Place in 2017. Step inside for a first class display that clearly delivers, also a free-to-enter cafe (which may help explain why none of the commercial units at Postmark are yet occupied). A separate building houses the entrance to Mail Rail, once the GPO's subterranean delivery service and now a ride-on circuit where you take the place of the sacks. Its builders 100 years ago had to deal with all kinds of underground obstructions including the River Fleet, which is why heavy mid-tunnel floodgates are a feature on your way round. Royal Mail still sort parcels here in the remaining building at the lower end of the site which has been decorated with the names of postal towns between the windows. I smirked when I spotted a UPS van parked outside the delivery bay, and oh the irony as a brown-clad youth hopped out to deliver a package to a resident living on the site of the postmen's former car park.
The dip of the land is particularly pronounced along Mount Pleasant, a concave road that predates the Post Office's arrival. The street pattern was once very dense here alongside the fetid waters of the Fleet, a labyrinth of slums including Fleet Row, Red Lyon Yard and Wine Street. The Fleet Sewer replaced the earliest culverts in the 1860s following the line of Phoenix Place and Warner Street, then a decade later the Fleet Relief Sewer added extra capacity under parallel roads. A bigger intrusion was the construction of Rosebery Avenue in the late 1880s, necessitating a viaduct to be built across the valley to speed up through traffic and requiring considerable local demolition. However walking underneath along Warner Street still feels like stepping back in time, especially the echoing vaults of Clerkenwell Motors and the bleakly open staircase that connects the bustle up top to the cycle-friendly street down below.
As we continue south, the moment when this was the edge of built-up London gets ever earlier. For Ray Street this was around 1700, although at the time it went by the far less salubrious name of Hockley-in-the-Hole. Here the contours of the Fleet encouraged the creation of an infamous resort for the working classes, a natural amphitheatre at the foot of Herbal Hill where the City's low-life gathered to participate in violent sports. It was known as the Bear Garden, a place to watch and cheer on fighting creatures now the South Bank had been cleaned up. A flyer from 1710 reveals that at one event two market dogs were set upon a bull, a mad ass was baited, then another bull was turned loose with fireworks attached to is hide and two cats tied to his tail. The programme of events often included bearfights, cockfights, swordfights and bare knuckle bust-ups, although the worst of the behaviour shifted to Spitalfields in 1756 and the worst you'll find today is a pub. Which is closed.
The Coach was previously The Coach and Horses, a basic joint oft frequented by Guardian journalists when they were based just round the corner. Their HQ is now flats and the London base for LinkedIn, while The Coach reopened as a gastropub in 2018 (think grilled rabbit and onglet steak) and is currently on its second refit. Of far more interest on this safari is the drain cover out front, which 20 years ago was in the middle of the street but is now safely embraced by an extended pavement. This is another fabled location where the Fleet can be heard flowing through the pipework beneath the street, the sound particularly clear at present even though there's been barely any rain of late, so if you've never experienced the rush of a lost river this is the prime location to visit.
And so we hit Farringdon Road, which is reached up a brief slope because the land round here's been substantially reconstructed since a stream once ran downhill. Farringdon Road is one of the great engineering projects of the 19th century, simultaneously creating a major thoroughfare, shielding the first underground railway and burying a river. It's breadth here is striking, opening out into an arched chasm that splits the cityscape as trains emerge from tunnels on the approach to Farringdon station. One nominal remnant from the old days is the span of Vine Street Bridge, no longer open to through traffic but a great place to drop your Lime bike. Of greater relevance is the Clerk's Well, a source of water for the medieval Priory of St Mary and which ultimately gave Clerkenwell its name. It was rediscovered during building works in 1924 and can now be seen through the window of a lowly sales office whose tiny lobby is occasionally opened by Islington Museum, hence I was chuffed to get a closer look in June.
While the Fleet Sewer follows Farringdon Road the historic interest remains on the east side of the railway. Turnmill Street is ancient enough to be named after watermills on the medieval Fleet, and by Tudor times was filthy enough to have become one of London's most prominent red light districts. It's been scrubbed up a lot since, including the purest of officeblocks on the corner where Turnmills nightclub once stood. As for Cowcross Street this was once the route for cattle fording the Fleet - here the Turnmill Brook - on their way to market at Smithfield. It's now a pedestrianised road which divides the two entrances to Farringdon station, with the tube on one side, rail on the other and chuggers in the middle. Crossrail's engineers had to take account of a sewer following a tributary of the Fleet which crosses beneath the southeast corner of the ticket hall, meaning extra care had to be taken when digging out the shaft.
It's just beyond the station that the Fleet officially enters the City of London and Farringdon Road becomes Farringdon Street. Which'd be a good place to pause, I think, before concluding this Fleeting series next week.