The Dearden Brook dips underground at Rosebank in a 90m long culvert to pass underneath a lake.
A deep pool after a small waterfall at the infall was passable by skirting around the egde, within a curtain of water sprayed down from the lake above.
An upmarket housing development now occupies the site above, but metal supports with rotting wood hanging from the crown must have once carried water pipes for industry above.
A pipe to drain down the lake can be seen, then it's a lower section, presumably an older bridge and the outfall.
The brook then travels through a cutting between people's back gardens, a short bridge full of metalwork and an open section before converging with the River Irwell.