The South Downs and North Downs are two ares of chalk downland in southern England. The downs run parralel to each other, and would once have formed part of the same dome-shaped chalk outcrop. Erosion, however, has removed the chalk between the two ridges, forming an area called the Weald.

The North Downs stretch about 100 miles from the Kent Downs inland from Dover and Folkestone through Surrey as far as Hampshire. Towns in the North downs are Maidstone, Sevenoaks, Westerham in Kent, Purley in Greater London, Epsom, Caterham, Redhill and Reigate, Dorking, Guildford, Godalming and Farnham in Surrey, and Basingstoke in Hampshire. The North Downs consist of gentle heights in some parts and of chalky scars, steep hillsides and deep valleys in others.

Horticulture is especially difficult near the steepest parts of the Downs, which are particularly alkaline, and it is therefore almost impossible to grow lime-hating ericaceous plants unless the soil has been reconstituted.

Tthe Weald is an area of rolling countryside that stretches over the counties of Kent, Surrey, and East and West Sussex. Its name derives from the Old High German wald, a wooded area.

The South Downs extend about 70 miles through East Sussex, West Sussex and part of Hampshire. Towns and villages are Eastbourne with its 575 feet-high headland Beachy Head, Lewes, Brighton and Hove, Shoreham-by-Sea, the village of Washington, Arundel and Midhurst.

The most famous cliffs of the South Downs, apart from Beachy Head, are the Seven Sisters, between Eastbourne and Seaford.