Guess the Place

[MartinR]

Yes, specifically the Old Fort.  A summary of the public history of the site is on Wikipedia at https://en.wikipedia.org/wiki/Fort_Halstead.  Location:

• Nat'l grid:   TQ 49925 59138
• Coords:      51°18'42"N, 000°08'59"E or 51.31161,0.14972
• Post code: TN14 7BP (but this may be non-geographic).

If you look on these old maps at Chatham Royal Dockyard, it is just a blank.  I did consider that site for GTP, but the river would have made it too obvious.   In an era before satellites and drones, and less general aviation, keeping military installations blank made intelligence gathering for a putative enemy harder.

[johnfilmer]

It’s Fort Halstead, near Sevenoaks

[Beachbum]

YMCA ? Tunbridge Wells ?

[MartinR]

@John, no, not the River Bourne.  I repeat: "Go west, young man".
@Beachbum, south of the LC&D

[Beachbum]

North or South of the London Chatham and Dover Railway?

[John Walker]

Is the nearby river, the River Bourne that runs near Hadlow at one point ?

[MartinR]

"Go west, young man, go west"¹ - well to be accurate it's nearer to WbyN. 
¹https://en.wikipedia.org/wiki/Go_West,_young_man

[John Walker]

Lenham area?

[MartinR]

Right John, you've now solved the clue "There doesn't look to be much there, but that is deceptive".  The Ordnance Survey at that period (and indeed until well after WWII) did not show details of military facilities on public maps.  Shoot, the Medway is nowhere near, but there is another river's headwaters a mile or so away.

[shoot999]

River Medway close by?

[johnfilmer]

Is it an area blanked out to prevent showing military details?


Maybe a fort or barracks?

[MartinR]

No, but the German connection is there, possibly also a French connection.  Keep in mind that the map is from 1892-1914.

[John Walker]

Set up as a dummy area to fool the Germans?

[MartinR]

Yes

[John Walker]

War related?