In 1667 the Dutch raided the Medway, then protected only by Upnor Castle. This started a program of work to protect Chatham
dockyard with the addition of Cockham Wood and Gillingham Forts which were built in 1669 and later in 1756 the Cumberland lines, defences around the dockyard, and Fort Amherst. Forts Pitt and Clarence were added in 1805 and then a ring
of forts was built around the south, north and east of Chatham dockyard between the late 1870's and 1900. These were based on a polygonal design for the land forts and a circular plan for the island forts on Darnet and Hoo.
||Part of the dockyard defence dating from 1669, replacing
Upnor Castle. Now vanished.
||There are some overgrown but visible remains of th 1669
fort built on the north side of the river opposite Gillingham.
|| These surrounded the whole east side of the dockyard
down to St Mary's Island. Now almost completely built over.
||Open, being restored.
||In use until 1828, then used as a hospital until 1919. The site has been used as a school since 1929 and although much of the structure has been built over parts of the walls and ditches still remain. Private.
||On the east bank of the Medway, it has a three storey
tower. Now converted to flats.
||On eastern end of the Isle of Grain. Demolished in 1962.
|Grain Dummy Battery
||South of Grain Fort, in fair condition.
|Grain Tower Battery
||Off shore of Grain Fort, in fair condition.
|| On the north-western tip of Sheerness Docks. Private.
|| On the north coast of the Hoo peninsula, it is now
a riding stable.
||The site was demolished in 1975.
In use until 1961, now private and closed.
|1876 - 92
||On high ground overlooking Chatham. In poor condition.
||Now used as a business centre, private.
||Near the coast east of Gillingham at Grange & Twydall.
||A circular fort on an island in the Medway built between
1861 and 1872. Armed with 11 seven & nine inch RMLs, manned by
a complement of 100. It can be visited by boat. Photo and map below.
||Same design as Darnet, 1km away on another island in
the Medway. Built on the site of a 17th century gun battery. Private. Photo and map below.