Chesterfield is a market town and a borough of Derbyshire, England. It lies 24 mi north of Derby, on a confluence of the rivers Rother and Hipper. Its population is 70,260 (2001), making it Derbyshire's largest town (the larger Derby being a city). It is located on the A61, 6 mi from the M1, and forms part of the Sheffield City Region.Chesterfield received its market charter in the year 1204, and is currently home to one of the largest open air markets in Britain. The area around the town sits over a large coalfield, which was mined from many surrounding collieries until the 1980s. Little evidence of the mining industry remains today, and the town's economy has moved towards the tertiary sector. The town's most famous landmark, which is visible from many viewpoints outside the town, is the distinctive 'crooked' spire of its predominantly 14th century church.