With about 1.2 million people, Surrey is the twelfth most populous English county, the third most populous home county, after Kent and Essex, and the third most populous in the South East, after Hampshire and Kent.
Surrey is a wealthy county due to economic, aesthetic, conservation and logistical factors. It has the highest GDP per capita of any English county, some of the highest property values outside Inner London, and also the highest cost of living outside of the capital.
Surrey is divided in two by the chalk ridge of the North Downs, running east-west. The ridge is pierced by the rivers Wey and Mole, tributaries of the Thames, which formed the northern border of the county before modern redrawing of county boundaries, which has left part of its north bank within the county. To the north of the Downs the land is mostly flat, forming part of the basin of the Thames. The geology of this area is dominated by London Clay in the east, Bagshot Sands in the west and alluvial deposits along the rivers. To the south of the Downs in the western part of the county are the sandstone Surrey Hills, while further east is the plain of the Low Weald, rising in the extreme southeast to the edge of the hills of the High Weald. The Downs and the area to the south form part of a concentric pattern of geological deposits which also extends across southern Kent and most of Sussex, predominantly composed of Wealden Clay, Lower Greensand and the chalk of the Downs.
Surrey is the most wooded county in England, with 22.4% coverage compared to a national average of 11.8% and as such is one of the few counties not to recommend new woodlands in the subordinate planning authorities' plans. Box Hill has the oldest untouched area of natural woodland in the UK, one of the oldest in Europe. Surrey also contains England's principal concentration of lowland heath, on sandy soils in the west of the county.