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.