The Northern Outfall Sewer (NOS) is a major gravity sewer which runs from Wick Lane in Hackney to Beckton Sewage Works in east London (east of Stratford); most of it was designed by Joseph Bazalgette after an outbreak of cholera in 1853 and "The Great Stink" of 1858.
Part of the route has been landscaped to form the Greenway
The Wikipedia page is [1]