The caves, or rather tunnels, are in the former Winchelsea Quarry in Dover. They comprise four parallel and evenly spaced tunnels driven in at right angles to the quarry face, with irregular linking cross tunnels and offshoots for latrines. Three of the tunnels then draw together and then two tunnels continue on, a shorter one with two 45 degree offsets heading towards the Westmount building while the other one heading for a smaller chalk quarry in Tower Hamlets is longer and more sinuous.
Referred to as the Winchelsea to Priory Hill caves shelter in planning documents, these were used as a shelter for 1350 people in the Second World War, and a local resident Gerald Sedgwick recalls his family taking advantage of the shelter’s 2 and 3-tier bunks regularly in preference to their back garden Anderson Shelter. There was hot and cold running water and flush toilets, and an above ground Decontamination Centre and First Aid Post with four rooms accessed via air locks and with gas curtain separation from one another. The tunnels themselves had “an overhead cover ranging from 25 to 90 feet” and were adapted and extended after the Munich crisis
The main tunnels were bored near the end of the First World War to test a rotary cutting machine, possibly a Whittaker machine, that could be used to drive tunnels on the Western Front. The advantage of cutting a test tunnel at Dover was to allow it to be also used as a “dug out”, as air raid shelters were often called at the time, to protect citizens from Zeppelin and Gotha bomber attacks. The tunnels at the time may have been called Priory Gallery. A 1923 newspaper recalled that “…the R.E. Tunnelling Company made a series of experimental tunnels between the chalk pit in Folkestone Road and the chalk pit at Tower Hamlets