Dorchester ( ) is the county town of Dorset, England. It is situated between the towns of Poole and Bridport on the A35 trunk route. A historic market town, Dorchester lies on the banks of the River Frome, in the Frome Valley, just south of the Dorset Downs  and north of the South Dorset Ridgeway, that separates the area from Weymouth, south.