Reigate ‘Caves’ are in fact two sets of mined tunnels, originally excavated for the extraction of silver sand, used primarily for glass-making. The East Mine has seen subsequent use as a munitions store in World War I, beer and wine storage and as a World War II Control Centre.
The West Mine was also used for the storage of wine and beer and was an air-raid shelter in World War II. Part of it is now in use as a rifle range by a local club. Public tours are organised on Saturdays in summer months by the Wealden Cave and Mine Society.
Both mine sites were developed after the cutting and tunnel through the hill were constructed as part of the new road and tunnel that opened in 1823.
The eastern site was originally excavated with the intention of providing storage space for the local brewery and the sand extracted a profitable byproduct. It was integral storage that connected directly into the back of a local hostelry. It has now been converted into a self-guided museum that covers both the local history of the site as well as some of the other local hearthstone and sand mines and the Croydon tramway. There are also exhibits including an Anderson shelter, the door from the Reigate town hall cold war bunker and artefacts from the time the site was an WW2 air raid shelter, including some rare emergency water storage tanks made from concrete.
The western site was mined for sand. The centre section collapsed spontaneously in the 19th century, causing a substantial depression in the castle gardens above. The remainder of the quarry is extant although some areas were backfilled in the 1980s to stabilise nearby properties. The site is used by a shooting club and is open for public guided tours. A new tunnel is due to be constructed that will reconnect the two branches of the mine so that tours are circular and provide an emergency exit route.