The following text is from the original listed building designation:
FARNINGHAM HIGH STREET 1. 5280 (south-west side) Folly in grounds of Mill House situated to TQ 5467 9/126 west of The Water Mill II GV 2. Probably dates from 1790. This is situated on a hill overlooking the Water Mill. To the left there is a network of low flint walls capped with red brick. To the right of this, approached up a steep bank are 3 octagonal turrets, the one on the extreme left built of flint and brick in a chequer work design with a stone crocket over surmounted by a ball finial. The central turret is truncated and is built of flint and brick. The right side turret, also of flint and brick has a crenellated parapet and arrow-slit windows. Double-headed lancet windows to right of this. On the extreme right is a summer house built of flint with stone dressings. The rear wall has a diaper pattern of stock brick and flint, having flint galleting. The front inside wall is lined with cockle shells. The window is a 'Gothic' painted arch with stone lights. A painted arch with stone quoins leads back to the hillside. Underneath the turrets and summer house are 2 chambers excavated out of the hillside. Both have round-headed brick entrances set in a flint wall. The chambers are brick lined. Air shafts lead up, presumably to the turrets. The left hand chamber has a very small lead cistern dated 1790 forming part of a pump. The other chamber has an ogee-headed arch at the end facing the entrance. Both were probably used for storing grain for the adjacent mill and the Folly thus had a practical as well as ornamental purpose.
Listing NGR: TQ5448867025
(1)

The folly was in an overgrown condition in 2010. (2)

In 2012 a building survey was carried out. The underground chambers were described as an icehouse. (3)

<1> English Heritage, List of Buildings of Special Architectural or Historic Interest (Map). SKE16160.

<2> Purcell Miller Tritton LLP, 2010, Farningham Mill Estate: Heritage Statement (Unpublished document). SKE25152.

<3> Lathams, 2012, Farningham Mill Estate: Level 1.5 Building Survey Report (Unpublished document). SKE25151.