The South Street Caves are believed to be 17th century in date, mainly on the basis of carved graffiti on the walls (the oldest is dated 1666, the year of the Great Fire of London, and the style of incised lettering could well be of that age), but could be older. They are excavated into the soft Folkestone sands at the top of the Lower Greensand, and may have been used originally to mine building sand. There are also traces of three well shafts which may be medieval in origin.
The caves are on two levels; a large upper level quadrilateral of tunnels, two of which have been fitted out with brick wine bins, and a lower level room at the base of a narrow stone cut staircase.
The wine vaults have 19th century brick wine bins, the oldest dated 1815, which were capable of storing around 700 bottles in total. They were owned by various tradesman when they were acquired by the Local Authority in 1912, who then continued to rent them out until the 1960s.
The lowest level is locally referred to as the “Mystery Chamber”, and is a circular hollowed out chamber with a stone bench carved around the edge. Given the age, it may have been used by a dissenting religious group.
The part-filled well shafts have symmetrical recesses in their walls that may have supported ladders or some form of constructional scaffolding, and there is soot staining from where some form of lit illumination could have been mounted.
A local preservation group took over the lease in 1970 and occasional public tours began, which nowadays are run by Dorking Museum in summer months. More details available at Dorking Museum.
Beneath Dorking’s streets is a honeycomb of cellars and storage tunnels dug from the soft sandstone. The moodily atmospheric South Street Caves are the most easily visited of these.
Dating probably from the early eighteenth century, but possibly earlier (a carved 1666 is considered unreliable), the caves also feature a well with a date of 1672 incised into it as part of an apotropaic hex charm designed to stop evil using it to rise to the surface; two other wells possibly sunk to replace it; Georgian storage tunnels and a 1921 entrance corridor.
They are first recorded in John Timbs’s, 1822 book A Picturesque Promenade Round Dorking, which states: “Dorking being situate on a sandy rock, abounds with deep and capacious caves or cellars which are extremely cold, even in the height of summer. The most remarkable of these is one on the left side of Butter Hill. On the side of the entrance, is a wide staircase curiously cut out of the rock and descending by 50 steps to a crystalline spring of water. About a century ago, an individual expended the whole of his property in digging this cave and, having just wasted several hundreds, he is said to have died in the poor house.”
Timbs was almost certainly correct: the physical evidence points to the (entirely manmade) caves being a underground folly. It appears that their creator, a resident of the nearby Great House on Butter Hill, initially planned a modest grotto chamber accessible down a few steps from his garden, but then decided to construct a small igloo-shaped room 60 feet below street level instead. This took advantage of an already existing well to furnish it with a subterranean spring in true Delphic style.
There is no evidence that the caves' creator did really die a pauper, but after his death the folly’s top level was expanded for use as wine and food storage vaults, which continued in use until the 1960s. Over the years the by then flooded lowest chamber attracted visits from the gentry and those working in the store area above, many of whom left superb carved graffiti, along with increasingly improbable stories of smugglers and a hidden river.
In the 1970s Dorking and Leith Hill Preservation Society began offering tours of the then unused caves. These lapsed early in the 2000s, but were revived by Dorking Museum in 2015.