The SINC includes the privately owned Highwood Hill,[1][2] and at the western end is a seven-hectare Local Nature Reserve owned by Barnet Council and managed by the London Wildlife Trust.

[3][4] The Local Nature Reserve is an ancient hay meadow habitat consisting of three fields, known as Nutt Field, Hen Mead and Nearer Slay Land, with hawthorn and blackthorn hedgerows.

[5][6] The main part of the site consists of a large area of uncultivated grassland and old hedgerows between Totteridge Common and Mays Lane, crossing Dollis Brook, which is also an SINC.

The site also hosts the declining skylark and several rare beetles and spiders.

[1] The Dollis Valley Greenwalk and London Loop cross Totteridge Fields.