The River Neckinger is a reduced subterranean river that rises in Southwark and flows approximately through that part of London to St Saviour's Dock where it enters the Thames. What remains of the river is enclosed and runs underground and most of its narrow catchment has been diverted into other combined and surface water sewers, flowing into the Southern Outfall Sewer and the Thames respectively. Course The watercourse drained first the seasonally wet (and occasionally flooded) ground at St George's Fields, now Geraldine Mary Harmsworth Park, in western Southwark. Its course was east as follows: it took the line of Brook Drive then passed by the Elephant and Castle, then passed the site of Lock Hospital, Kent Street. This upper section was also known before that hospital's closure in the early 19th century as the Lock Stream. It then passed the grounds of (since demolished) Bermondsey Abbey to the south, forming the channel north of what was the large Thames island of Bermond's ey (island). The channel is today resembled by Abbey Street. In the first millennium the river merged into the Thames by hooking north at three points. At least three tidally broadly flooded mouths existed, two of which were west of the former small island of Horsleydown and the third at the approximate site of St Saviour's Dock. The Neckinger's northern mouth (now a surface water point of discharge into a deep, excavated inlet) divides the much-built up former marshland at the east end of Horsleydown island, known as Shad Thames and the low part of Bermondsey historically known as Jacob's Island to the east, which has also been built-up. History Etymology In the 17th century convicted pirates were hanged at the wharf where the Neckinger entered the Thames. The name of the river is believed to derive from the term "devil's neckcloth", a slang term for the hangman's noose. In London Past and Present, published in 1891, Henry B. Wheatley argued that there was 'much good evidence' that 'the 'Devil's Neckinger'... the ancient place of punishment and execution' was at the site of the 'Dead Tree public-house' on Jacob's Island. Writing in The Inns of Old Southwark And Their Associations, in 1888, authors William Rendle and Philip Norman note that a place called Devol's Neckenger appears on a map in 1740 and, in the same location, in 1813, the Dead Tree inn. Canute's Trench Historian Walter Besant