The River Bollin is a major tributary

Tributary

A tributary or affluent is a stream or river that flows into a main stem river or a lake. A tributary does not flow directly into a sea or ocean...

 of the River Mersey

River Mersey

The River Mersey is a river in North West England. It is around long, stretching from Stockport, Greater Manchester, and ending at Liverpool Bay, Merseyside. For centuries, it formed part of the ancient county divide between Lancashire and Cheshire....

 in the north-west of England

England

England is a country that is part of the United Kingdom. It shares land borders with Scotland to the north and Wales to the west; the Irish Sea is to the north west, the Celtic Sea to the south west, with the North Sea to the east and the English Channel to the south separating it from continental...

.

It rises in Macclesfield Forest

Macclesfield Forest

Macclesfield Forest is an area of woodland, predominantly conifer plantation, located around south east of Macclesfield in the civil parish of Macclesfield Forest and Wildboarclough, in Cheshire, England. The existing woodland is the last substantial remnant of the Royal Forest of Macclesfield, a...

 at the western end of the Peak District

Peak District

The Peak District is an upland area in central and northern England, lying mainly in northern Derbyshire, but also covering parts of Cheshire, Greater Manchester, Staffordshire, and South and West Yorkshire....

, and can be seen in spring form, from the Buxton

Buxton

Buxton is a spa town in Derbyshire, England. It has the highest elevation of any market town in England. Located close to the county boundary with Cheshire to the west and Staffordshire to the south, Buxton is described as "the gateway to the Peak District National Park"...

 to Macclesfield road. The stream then descends the 10 miles (16 km) through Macclesfield and Wilmslow

Wilmslow

-Economy:Wilmslow is well known, like Alderley Edge, for having many famous residents, notably footballers, stars of Coronation Street and rich North West businessmen. The town is part of the so-called Golden Triangle in the north west together with Alderley Edge and Prestbury...

 where it has a confluence

Confluence (geography)

In geography, a confluence is the meeting of two or more bodies of water. It usually refers to the point where two streams flow together, merging into a single stream...

 with the River Dean

River Dean

The River Dean rises at Longclough in Macclesfield Forest on the western edge of the Peak District foothills above the village of Rainow in north east Cheshire, England.Together with a number of tributary streams it is impounded by the dam at Lamaload...

, near to Styal Prison

Styal (HM Prison)

HM Prison Styal is a Closed Category prison for female adults and young offenders, located in the village of Styal in Cheshire, England. The prison is operated by Her Majesty's Prison Service.-History:...

. For the following 10 miles (16 km) it defines the southwestern portion of the border between Greater Manchester

Greater Manchester

Greater Manchester is a metropolitan county in North West England, with a population of 2.6 million. It encompasses one of the largest metropolitan areas in the United Kingdom and comprises ten metropolitan boroughs: Bolton, Bury, Oldham, Rochdale, Stockport, Tameside, Trafford, Wigan, and the...

 and Cheshire

Cheshire

Cheshire is a ceremonial county in North West England. Cheshire's county town is the city of Chester, although its largest town is Warrington. Other major towns include Widnes, Congleton, Crewe, Ellesmere Port, Runcorn, Macclesfield, Winsford, Northwich, and Wilmslow...

 before merging with the River Mersey

River Mersey

The River Mersey is a river in North West England. It is around long, stretching from Stockport, Greater Manchester, and ending at Liverpool Bay, Merseyside. For centuries, it formed part of the ancient county divide between Lancashire and Cheshire....

 north of Lymm

Lymm

Lymm is a large village and civil parish within the Warrington borough of Cheshire, in North West England. Lymm was an urban district of Cheshire from 1894 to 1974. The civil parish of Lymm incorporates the hamlets of Booths Hill, Broomedge, Church Green, Deansgreen, Heatley, Heatley Heath, Little...

.