Dartford is the principal town in the Borough of Dartford, Kent, England. It is located 18 mi (29 km) south-east of Central London and is situated adjacent to the London Borough of Bexley to its west. To its north, across the Thames estuary, is Thurrock in Essex, which can be reached via the Dartford Crossing. To its east lies the Borough of Gravesham and to the south the district of Sevenoaks. It had a population of 51,240.