Description:

 

The Maunsell Naval Sea Forts were designed to provide anti-aircraft defence in the Thames estuary after the Luftwaffe began their raids on London in 1940. The Thames estuary was not as heavily defended as Dover and the south coast and therefore presented a much easier approach to London for German bombing raids.

 

Fort Knock John, the last of the four Naval Sea Forts, was constructed at a disused cement works on the south bank of the Thames between Northfleet and Gravesend on the Kent Coast. Access to the Thames was therefore immediately available. The forts were constructed in dry dock then floated out to their designated site in the Thames Estuary and grounded.

 

 

Fort Knock John
 

 

Red Sands Sea Fort

Archcliffe Cells

Ellington Girls Shelter

Langdon Hole

Grain Tower Battery

Fort Knock John

HMS Wildfire

Wartling Bunker

Yaverland Battery

Hoo Fort

Snape Mine

Marden Mine

SF Deep Shelter

SF Magazine No 1

Detached Bastion

Upper Oil Mills