[1] The hill is a lower greensand Cretaceous outcrop situated amongst Jurassic strata of marl and clay, at the border between the chalk of South-East England and the granite of Devon and Cornwall.

Surveys were also carried out by the National Trust in 1982, the Royal Commission on the Historical Monuments of England in 1995,[2] and the University of Bournemouth in 2016.

[citation needed] In 1795–7 Dorothy and William Wordsworth lived at Racedown House—a property of the Pinney family—to the west of Pilsdon Pen.

They walked in the area for about two hours every day, and the nearby hills—including Pilsdon Pen—consoled Dorothy as she pined for the fells of her native Lakeland.

She wrote, "We have hills which, seen from a distance almost take the character of mountains, some cultivated nearly to their summits, others in their wild state covered with furze and broom.