A section of brick wall, held together by tree roots, and a wooden gate beside it.
Marked on MAGICmap as a sluice but there is no stream (or drain) here any longer. The construction is surrounded by a number of brick walls and by what appears to once have been a building, with evidence of a wooden gate beside it. See also >
Link. 19th century maps show this location as the site of an engine house. I am guessing, but to my untrained eye the mechanism seems to indicate that water was perhaps once being pumped here? (I would be grateful for information as to what exactly this is, or rather, has been.)