The New River is an artificial waterway in England, opened in 1613 to supply London with fresh drinking water taken from the River Lea and from Chadwell Springs and, originally, Amwell Springs, as well as other springs and wells along its course.
The river follows the land contours, although certain parts have been straightened over the centuries. Although at one time threatened with closure, that decision was reversed and the waterway continues to supply water to the capital.
There is a designated walking route along the canal called the New River Path. It is a 28-mile long-distance footpath which follows the course of the New River from its source in Hertfordshire to its original end in Islington, London.
Wikipedia https://en.wikipedia.org/wiki/New_River_(England)
Coordinates 51°48'24.722" N -0°3'28.352" E