Named after Vortigern, the 5th century British King who is reputed to have given Thanet as a bridal gift to his future son-in-law Hengist (of Hengist and Horsa fame), the caves are said to have been found by a gardener digging in the garden of Northumberland House in or around 1798. Some versions of the story have the gardener falling into the caves in the process and dying of his injuries.
The owner of Northumberland House, Francis Horster, was an eccentric man, and the lure of owning his own Picturesque curiosity led him to create a new entrance with stairs. He then used the caves as a wine cellar and personal grotto, and had them decorated with large murals by a local artist named Brazier. Brazier’s paintings of wild animals, a pair of redcoats guarding a doorway, a hunting and other scenes are boldly executed and look younger than their age, possibly through a process of occasional touching up.
After Horster’s death the caves were neglected for several decades until a tenant in 1863 turned them into a tourist attraction under the name Vortigern’s Cavern, charging the princely sum of 3d for entrance.
Northumberland House later became the vicarage, and a new entrance and set of stairs from its cellar, the current means of access, was created in 1914 as a private access to the caves in the event of air raids. This was very prescient as Thanet would later become the most heavily bombed part of Britain in the First World War. The public were also allowed access for shelter purposes but used the Horster-era stairs. The caves reopened as an attraction after the war, and then once again became an air raid shelter for the Vicarage in the Second World War, until both Vicarage and the adjacent church were destroyed by bombing in June 1943.
In an almost dreary round of repetition, the post-war history of the caves runs from immediate post-war abandonment, a half century as a tourist attraction following its reopening in 1958, and then closure again in 2004 by the local authority, its new owners, this time for unspecified health and safety reasons.
In recent years, the origin of the caves has been thoroughly investigated and it is believed that they started as a chalk mine for agricultural or building purposes, using a rectangular shaft, something that was unusual for a denehole.
The caves’ archaeologist, Rod Le Gear, has said that from this “initially three headings were commenced heading north, east and west. A fourth heading to the south was started lower down but before the other headings had exceeded about 1.5m. The mine was then excavated on a ‘pillar and stall’ system where galleries are dug at right angles to each other to leave large pillars of untouched chalk to support the ground above. The galleries are some 8.0m high and would have been worked in a series of benches or platforms. It was these abandoned workbenches in some other chalk mines such as at Chislehurst that prompted early writers to interpret them as ‘Druid’s Altars’. Tool marks indicate that the Caves were dug with a short-headed wrought-iron pick and that the miners were right handed. The northern and two western galleries were not developed to the full depth of the rest of the excavation. It is possible that the mine was initially dug to the depth of the north and western galleries and then a second ‘lift’ was taken later and the floor brought down another 3.0m. Why the north and western galleries were left is unclear, although the most likely reason was that no further chalk was required from the site and the mine was abandoned before those galleries were finished”.
He also believes that the long gallery lengths show that some form of underground transport, probably a wheelbarrow, would have been used to carry the chalk from the working face back to the shaft, and that this combined with a distinct pattern of rope grooves seen on the roof beside the shaft date the mine to the late 17th or early 18th century.
Curiosities include a well, used in more recent times as a wishing well and clogged with offerings. A Kent Underground Research Group dig in 1993 got back down to water level at 13m below the adjacent cave floor. They also found an unexpected side connection with a cesspool and the archaeologist concluded that this was an attempt to avoid having to empty the cesspool by allowing it to discharge into the “hopefully disused” well.
Meanwhile several ovoid pits, the so-called ‘Dungeons’, which consist of rectangular openings over cylindrical pits several metres deep, have been described as either lock-ups or malt kilns, but both explanations have problems. Their likeliest origin is as ice-wells dug by Horster.
The caves are currently closed though there is a strong local action group and hopefully they will be reopened soon. More details are available at Margate Caves.