I learned recently that "our" Reigate Hill underground Battle HQ known as Monty's Hideout was the inspiration for the secret tunnels of South Heighton on the South Downs for the Navy - started and completed soon afterwards in 1941.
Geoffrey Ellis describes this as follows:
'Col. FH Foster DSO OBE TD RL RIBA CRA 4 Corps Troops Royal Engineers disclosed how he designed the subterranean labyrinth after visiting Montgomery's headquarters at Reigate."
Haven Life, March 2006 page 19.
Take a look at the photos - it's a magnificent story of perseverance and restoration. The South Heighton site was eventually recognised as being of National Importance by English Heritage.
A little snippet of information I like is that one of the secret entrances was disguised a chicken coop.
Now then, how about its inspiration, here in Reigate?