Hankley Farm is a 2.4-hectare (5.9-acre) biological Site of Special Scientific Interest (SSSI) west of Elstead in Surrey.

[1][2] This sandy arable field has been designated an SSSI because of its large population of a nationally endangered plant, red-tipped cudweed.

This was formerly a common weed on arable fields, but it has been in sharp decline since the 1960s.

The colonies in the site and neighbouring fields may represent as much as 50% of the British population.

[3] The site is private land with no public access.