Nothing in the metropolis is more lost than the historic rivers that once fed the Thames. And none is more historic or more lost in geography or imagination than the River Tyburn, which once flowed openly from Hampstead’s hills across Regent’s Park and Green Park to form an eyot called Thorney Island. On these few acres stood Westminster Abbey and its monastery, the royal palace (until Henry VIII moved out), the emerging Houses of Parliament and Westminster School. No parcel of land in Britain, and maybe anywhere, contains more history in such a small space.
I say “once flowed” but, of course, the Tyburn still does until it goes underground and gets swallowed by Sir Joseph Bazalgette’s amazing sewer system and its interceptor channels, which pipe what is left of the Tyburn to sewage works in East London at a point shortly before it used to empty itself into the Thames. The only bit of it that occasionally reaches the Thames now is the western extension from around Buckingham Palace to a few hundred yards west of Vauxhall Bridge, where you can still see the outlet through which surplus water enters the Thames during storm conditions. You can also still see the sluice gate keeper’s house, now converted into a des res called Tyburn House close by the exit.
Archaeologists are still arguing about the eastern route of the Tyburn after it leaves Buckingham Palace to flow roughly under Tothill Street to old Westminster, as new archaeological digs throw up new evidence of the mix of Thames and Tyburn waters which spawned lots of small eyots. But if you walk from the Embankment opposite Victoria Tower Gardens along Great College Street, the original medieval wall along which the Tyburn route ran is still there on your right.
And when you get to the entrance to Dean’s Yard, you are passing over the remains of an ancient bridge near which the remains of a 14th Century pillar can still be found in the bowels of Church House. Thereafter, the Tyburn skirted the walls of the old monastery, along what used to be called Longditch (today’s Storey’s Gate) and partially up Whitehall before turning right into the Thames before reaching Downing Street.
Whether the Tyburn can still be called a river when it contains so much sewage and doesn’t properly reach the Thames is a matter for linguists as well as archaeologists, but there is no doubt that waters still emerge from the Hampstead hills and, in storm conditions, produce a lot of water that in olden days would have been part of the Tyburn. You don’t need much imagination to sense that it is still there.