A feature visible only on the Epoch 3 (1909) edition of historic 1:2500 Ordnance Survey mapping [1], labelled as ‘Splinter Proof’, has been given a monument polygon during historic mapping enhancement as part of Phase 1 of the South East Rapid Coastal Zone Assessment Survey. Epoch 4 (1938) mapping is not available for this area [2], and no such feature is visible on MasterMap (2009) [3].
The feature is a sub-rectangular mound of gravel/shingle(?) with a flat square platform on top. It has a maximum dimension of 13m by 11.6m.
This feature is part of a much wider area of similar features around Holmstone and South Brooks that indicate an early military site used for artillery practices.

<1> Ordnance Survey, 1905-10, Ordnance Survey 1:2500 3rd edition: 1901-1912, 1909/1:2500 (Map). SWX11833.

<2> Ordnance Survey, 1928-1947, Ordnance Survey 1:2500 4th edition 1928-1947, 1938/1:2500 (Map). Ske12644.

<3> Ordnance Survey, 2009, OS MasterMap, 2009/MasterMap (Cartographic materials). SWX15710.