Build around 1790 this tunnel was built underneath the Castlefield Basin to deal with the excess waters of the River Medlock not used to supply water to the Bridgewater Canal.
All Ova is the last culvert of the Sudden Brook before it flows into the River Roch, it's pretty long at 900m and mostly big CMP although not all of it is walkable.
This old culvert built mostly of brick and stone takes the Sudden Brook around 550m through Rochdale.
The River Medlock flows through Manchester City centre taking a meandering route through open air and the Spartacus and Budge culverts.
A rag laden grill conceals a large outfall flap on the bank of the Irwell just upstream from Manchester City Centre
Worsley has a rich industrial heritage in which it's brook played an important role. The Worsley Brook flows from Old Warke Dam and goes underground for around 350m.
The River Medlock flows from Strinesdale Reservoir into a stone cascade, it drops down into a series of three culverts.