Two further purchases of and transferred Lodge Hill and Ashurst Rough to National Trust ownership in 1921 and 1923. Following World War II, National Trust acquired Headley Heath, a geologically distinct area of heathland which lies to the north-east of Box Hill village, the majority of which was given as a single donation in 1946. The Trust continued to purchase land, and by the mid-1980s the estate comprised some . The most recent additions to the Box Hill Estate include farmland at Westhumble and at the foot of the hill, purchased in the late 1990s.