Dorchester is the county town of Dorset, England. It is situated between Poole and Bridport on the A35 trunk route. A historic market town, Dorchester is on the banks of the River Frome to the south of the Dorset Downs and north of the South Dorset Ridgeway that separates the area from Weymouth, 7 miles to the south. The area around the town was first settled in prehistoric times.