Thursley, Hankley and Frensham Commons is a 1,878.5-hectare (4,642-acre) biological Site of Special Scientific Interest west of Godalming in Surrey.

[1][2] Thursley and Hankley Commons are Nature Conservation Review sites, Grade I.

[3] An area of 115.1 hectares (284 acres) is a local nature reserve called The Flashes[4][5] and an area of 180 hectares (440 acres) is the Elstead Group of Commons, a nature reserve managed by the Surrey Wildlife Trust.

[10] This site is of national importance for its invertebrates, birds and reptiles, and is mainly heathland but the valley mire on Thursley Common is one of the best in the country.

The site is one of the richest in southern England for birds and of outstanding importance for reptiles, such as the nationally rare sand lizard.