During World War 2, the Deepdene hotel and grounds were taken over by Southern Railway who had chosen the site to be its emergency wartime headquarters. Making use of some existing caves, which had been there for some 300 years, building work started to turn the chalk tunnels into a bomb-proof underground control centre.
In order to keep the operations secret, the hotel retained its name and even continued to take booking enquiries throughout – of course no holidaymakers actually stayed there – but there was a big clue about the site; a 99ft mast was erected in the hotel grounds to support radio communications. Inside the caves, which had to be extended, staff were based there around the clock. A control room, switchboard, ventilation system and other amenities were installed for the staff who were relocating from Waterloo. There were three entrances plus an emergency exit which is accessed by a 90ft spiral staircase.
If any of Southern’s railway lines were damaged during the war, they could manage contingencies from this bunker to ensure that goods or traffic could still travel. Each room had a radio receiver, in case any emergency announcement was made by the Government. Southern Rail remained at the hotel until the 1960’s and the building itself was demolished at the end of the decade, leaving the tunnels forgotten until near the end of the century.
Firefighters discovered the tunnels in 1997 whilst responding to an emergency call and came across a large amount of asbestos – so much that their uniforms had to be incinerated. Subbrit were given rare permission to break into the tunnels (yes, literally break in) after they had been sealed following the fire. They were allowed to take photos on the condition that the entrance was resealed after their visit.