TN postcode area TN postcode area The TN postcode area, also known as the Tunbridge Wells postcode area, is a group of 40 postcode districts in England, which are subdivisions of 24 post towns. These postcode districts cover an extensive area from the Greater London border at Westerham to the Sussex coast, including south Kent (including Royal Tunbridge Wells, Tonbridge, Ashford, Sevenoaks, Cranbrook, Edenbridge, New Romney, Romney Marsh and Tenterden) and northern and eastern East Sussex (including Hastings, Battle, Bexhill-on-Sea, Crowborough, Etchingham, Hartfield, Heathfield, Mayfield, Robertsbridge, Rye, St Leonards-on-Sea, Uckfield, Wadhurst and Winchelsea). Additionally, small parts of TN14 and TN16 cover the rural
Whitstable and South Street at the south. Chestfield has its own parish council. An area of protected woodland and grassland called Duncan Down lies to the south-east. The geology of the town consists mainly of London Clay (which covers most of North Kent). Much of the centre of the town is built on low-lying marshland. Sea walls are in place to prevent coastal flooding. The land in the east is higher, with slopes down to the coast at Tankerton. The whole of the north-east Kent coast has been designated a Site of Special Scientific Interest. A very unusual (some say unique)