Sea Forts of the English Channel

"the sea forts"
Tim Mitchard, The UTATAN

"About a year ago I was going through some old negatives and came across some that I had taken 15 or so years ago. These were of the Sea Forts located in The Thames Estuary off the North Kent coast...."

The rest is an interesting (to me, anyway) account of these relics of WWII. It's a bit lacking in documentation - that's the boring stuff about where information comes from, that lets the reader know that the author didn't make up the facts.

But that's nit-picking. It's a good read: and a pretty good start for someone who is seriously interested in researching these strange structures.