The Holcombe Brook drops underground in a couple of culverts, the first of which is around 280m long and features several waterfalls and cascades.
The Walshaw Brook emerges briefly into the open air from Slop Pail before returning underground for the last stretch to the River Irwell
A concrete CSO chamber with an Archimedes' screw next to the Parr Brook.
A main overflow for the Work 6 Sewer with a dose of big scale Manchester brick.
This is the drain that got me into draining. I found a dark filled entrance, heard the water and smelt the culvert smell. After heading back a bit more equipped I went in and got my first taste of an underground river.