London has many long gone rivers which have been diverted and 'lost' during the constant expansion of the city.
The River Tyburn originated in Hampstead, north London, and flowed through Regent's Park, continuing under Buckingham Palace, and reached the Thames in Pimlico (near Vauxhall Bridge). Today, the Tyburn is a sewer officially titled the King's Scholar's Pond Sewer.
There is still somewhere to see the River Tyburn (and not as a sewer) in the basement of an antiques shopping center, just off Oxford Street.
Grays Antiques, near Bond Street, has a small section of the Tyburn on display and there are goldfish swimming in it so it's much cleaner than expected. Interestingly, the building had been Bolding & Son plumbers before the antique dealers moved in back in 1977, and the first thing they had to do was to drain six feet of Tyburn water from the basement.
The Ty- in Tyburn derives from a word for "boundary" and there was an area in Marylebone recorded as Tyburn in the Domesday Book, written nearly 1,000 years ago.
Earlier names of Oxford Street and Park Lane were Tyburn Road and Tyburn Lane respectively. At the junction of Oxford Street and Park Lane is Marble Arch and this was the location of the notorious Tyburn Tree - popular hanging gallows for public executions from 1571 to 1783. It is suggested that the River Tyburn, by Gray's Antiques, was once a well-known spot for reviving criminals who had been unsuccessfully hanged at the gallows.
The suggestion continues that ghosts are still said to walk through the river at night but the current antique dealers told me they hadn't seen anything.
Grays Antiques has over 200 antique dealers, across two floors, and in two buildings. It is close to Bond Street tube station and is closed on Sundays.
Grays is at 58 Davies Street and at 1-7 Davies Mews, London, W1K 5AB. The River Tyburn can be seen in the basement of the Mews building.
The Tyburn Convent is nearby at Marble Arch and has a shrine to the Catholic martyrs who were executed at the Tyburn gallows.