The River Westbourne is one of London's lost rivers. The full route originally ran from Hampstead in the north, through Hyde Park via the Serpentine, before gushing out into the Thames around the Chelsea area.
It was changed when Queen Catherine wanted to re-landscape Kensington Gardens to create the Italian Fountains. At this point she decided to damn the Westbourne where it entered the park, effectively creating what is today known as the Long Water.
Today, following developments in the Belgravia, Chelsea and Paddington areas, the River Westbourne runs largely underground, although it can be briefly seen at several points in London, most noticeably in a nineteenth century iron pipe which allows it to flow above the platforms of Sloane Square station on the District and Circle Line.