[1][2] One area of 6.9 hectares is owned and managed by the London Wildlife Trust.

It is a steeply sloping 55 acre biological site, which is close to Charles Darwin's home, Down House, and inspired him and provided him with a picnic place.

The site was notified to Natural England in 1985, but by 1999 it was in danger of being lost through neglect, and the London Wildlife Trust launched an appeal to save it.

The trust aimed to buy the whole site, but only succeeded in purchasing part of it amounting to seventeen acres.

[6][7] There is access from Hanbury Drive and the road Saltbox Hill.