Manchester is built on a flat plain 35 miles from the coast on the west side of the Pennines . To the east are the Pennies a wild moorland area made up of millstone grit. The main river is the River Irwell which joins the River Mersey at Irlam. The grit which lacks lime means the water is very soft and was a feature in the early textile processing that built Manchester 's wealth. To the west are the flat plains of Cheshire and Lancashire.
The market towns of Stockport, Bolton and Bury that surround Manchester developed as a result of the streams that flowed into them from the surrounding hills.
Manufacturing in Manchester had a significant toll on the environment with pollution of waterways, and air being a problem in the 1950's. A major effort including bringing in water from the Lake District and clearance of slums has transformed the city centre in recent years.
