There are two river gaps: the Rivers Ouse and Cuckmere.

Between the Downs and Weald is a narrow stretch of lower lying land; many of the rivers and streams occupying this area originate in the Weald.

The High Weald is heavily wooded in contrast to the South Downs; the Low Weald less so. The location of settlements in East Sussex has been determined both by its history and its geography.

Three are larger, rural, districts (from west to east) are: Lewes; Wealden; and Rother. The rural districts are further subdivided into civil parishes.

From a geological point of view East Sussex is part of southern anticline of the Weald: the South Downs, a range of moderate chalk hills which run across the southern part of the county from west to east and mirrored in Kent by the North Downs.

To the east of Beachy Head lie the marshlands of the Pevensey Levels, formerly flooded by the sea but now enclosed within a deposited beach.

At Bexhill the land begins to rise again where the sands and clays of the Weald meet the sea; these culminate in the sandstone cliffs east of Hastings.The highest point of the Downs within the county is Ditchling Beacon, at 814 feet (248 m): it is termed a Marilyn.The Weald occupies the northern borderlands of the county.Peacehaven and Seaford are more dormitory towns than anything else.Away from the coast lie former market towns such as Hailsham, Heathfield and Uckfield; Crowborough is a centre for the Ashdown Forest.In 1974 East Sussex was made a non-metropolitan and ceremonial county, and the three county boroughs became districts within the county.