The treeless summit of Black Down is a popular viewing point, crowned by the 72 foot (22 m) high Hardy Monument built in 1844 in memory of Vice-Admiral Sir Thomas Masterman Hardy who was Admiral Nelson's Flag Captain at the Battle of Trafalgar.

[2] From the top there are views of the Fleet and Chesil Beach as well as the South Dorset Downs.

Geologically, Black Down is the western tip of the Bagshot gravel beds.

Dolines are usually shaped like a teardrop cut in half vertically and laid down horizontally.

Within 1,000 m (1,100 yd) of the monument there are three dolines which were formed by the chalk being dissolved in a vertical fissure in its structure.