Fort Darnet is a nineteenth-century military installation on the River Medway in Kent, England, that formed part of the defences of Chatham Naval Dockyard.

[2] The forts were originally designed for two tiers of guns mounted in a circle, with a boom strung between them, but there were many problems with subsidence.

After extensive cost overruns they were completed in 1872 with one tier of eleven guns: a mixture of eight 9-inch and three 7-inch rifled muzzle-loaders.

[1] The fort was used for gunnery practice until one of the guns cracked in its casemate, as reported in ‘The Chatham Observer’ on 25 January 1879.

[2] In the Second World War the fort was used as an observation post, with platforms and pillboxes built on top.