 In Roman Britain, with the exception of two modern fields, "the Romans were exploiting coals in all the major coalfields in England and Wales by the end of the second century AD".Evidence of trade in coal, dated to about AD 200, has been found at the Roman settlement at Heronbridge, near Chester; and in the Fenlands of East Anglia, where coal from the Midlands was transported via the Car Dyke for use in drying grain.Coal cinders have been found in the hearths of villas and Roman forts, particularly in Northumberland, dated to around AD 400.