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There are more questions than answers... Discovered by chance in 1835, the  subterranean Shell Grotto’s curving chalk walls are studded with 4.6 million shells. They create a magical mosaic of strange patterns and symbols.
Was this a place of worship, a setting for secret meetings or an extravagant folly? We don’t know who built this amazing place, or why, but since the first paying customers descended the chalk stairway in 1838, debate has raged about the Grotto’s origins.
For every expert who believes it to be an ancient temple, there’s someone else convinced it was the meeting place for a secret sect; for every ardent pagan, there’s a Regency folly-monger ready to spoil their fun.
At first glance the Grotto’s design only adds to the confusion, with humble cockles, whelks, mussels and oysters creating a swirling profusion of patterns and symbols. A storehouse for the imagination, there are any number of interpretations; trees of life, phalluses, gods, goddesses and something that looks very like an altar, to name but a few.

However, there’s only one fact about the Grotto that is indisputable: that it is a unique work of art that should be valued and preserved, whatever its age or origins.

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There are conflicting accounts about how the Grotto was found, although most agree on a date of 1835. The earliest reference to the discovery appears in the Kentish Gazette of 22nd May 1838, announcing its forthcoming opening as a public attraction. The circumstances are described simply, referring to a gentleman having recently purchased Belle Vue Cottage and making alterations which involved excavating a few feet. During this operation the workmen were impeded by a large stone and an examination followed, resulting in the discovery. 


Perhaps the best account of the discovery comes from Frances Newlove. Frances was the younger daughter of Joshua, widely reported as the discoverer of the Grotto. She was around 12 years old when the events she recalls below occurred. She took over the running of the Grotto just before her father James’s death and was proprietor for a number of years.

'My brother found out about the underground place sometime before it was known. He never dared to tell father. He found the chalk loose at one end of the passage next to the cottage, which was built afterwards, and he opened it up by taking the stuff away, as it were in rough blocks. Then when the opening was wide enough, he crawled through and got into the Grotto. And so did I. Yes, and two or three other young girls too. We crept in through the opening, and had to scrub ourselves right through the dirty chalk, and lor, we did make a mess of ourselves. But we got in and saw it all; we had to take a candle in a lantern round somebody’s neck.


But it was really discovered in 1837, and my brother was dropped down the Dome with a light. He had been through it before, but had not told father.'


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Before experiencing the Grotto, visitors descend into the Museum Room. Here, we set the scene for what’s to come, answer questions about the Grotto, explain our conservation work and share some of the items from our archive. We also have a small but perfectly formed collection of shell art from around the world on display.


Our colour panel greets visitors, made to demonstrate the bright colours of the Grotto when it was first made. We encourage visitors to touch this panel – the Grotto is very fragile and mustn’t be touched – so if you want to feel the mosaic, this is where to do it!


We have interactive elements in this room too: an original Victorian stereoscope to look through, a colouring table, and our shell magnet board is coming soon, where you can make your own shell mosaic designs.


Check out the Georgian chest of drawers for more in-depth reading, plus large print and foreign language versions of all the information.

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Follies and shell structures were popular in the 1700s. There are lots of them dotted around the country, largely in the grounds of stately homes as a result of wealthy landowners having embarked on the Grand Tour and seen shell structures on their travels. Those who believe the Grotto is devotional and/or older argue:

- The land the Grotto lies under was farmland and, as far as we know, has never formed part of a large estate. So why would a rich man’s fancy be built under someone else’s pastureland?

- Follies were built as a statement: look at how much money I have, look at how cultured I am, look at me! So, if they included shells, the more exotic the better. In general, they weren’t secret, hidden away places.

- If the Grotto had been built in the 1700s, is it possible that all knowledge of it had disappeared by the time of its discovery in 1835? The building of the Grotto would have been a mammoth task: the excavation of the passageways, transporting 4.6 million shells to the site, sorting those shells and enlisting enough labour to create the mosaic. How to do all this on rising open ground, next to a busy track without anyone noticing?


There was certainly a good deal of smuggling going on in and around Margate, but it’s impossible to imagine the Grotto being a useful hiding place. For one thing, it’s a fair distance inland from the coast with no tunnels extending to or from the cliffs, nor any providing entrance or escape routes to nearby houses. The idea that smugglers would bring their booty to an exposed field doesn’t hold water. And why decorate it with millions of shells?


They could. However, we have been advised by experts in this field that we would need to provide a number of samples (to mitigate against dating a Victorian – or later – repair) and the cost is high. Right now, there are more pressing conservation priorities.


Nearly all of the 4.6 million shells are native to the British Isles and most of those could be found relatively locally. These include mussels, whelks, oysters, cockles, limpets and razor shells. There are some exotic shells, such as the queen conches from the Caribbean in the corners of the Altar Room.


During our 2009 condition survey, five mortar samples were sent off for analysis – each one was found to be different, which could be explained by successive repairs. Some samples were identified as lime mortar, some described as ‘Roman cement type’. You’ll notice bare patches, often circular, around the Grotto. These are small slates that may have been mosaiced at ground level – where, presumably, the working conditions would have been much more pleasant – and then attached to the chalk. Where the mortar is visible on these roundels, it is Plaster of Paris which has proved less effective, hence the bare patches. We’re currently re-making these missing roundels.


The Grotto was lit with gas lamps for nearly 100 years. Indeed, when the Grotto was auctioned in 1932, the catalogue referred to 'wonderful catacombs illuminated with incandescent gas'. The gas lighting was probably wonderfully atmospheric, but has left the shells covered in carbon deposits.

While the shells could be cleaned this would introduce a great deal of moisture, which is the last thing the Grotto needs. Also, beneath their layer of soot, most of the shells appear to be white – shells lose their colour in damp conditions. So cleaning would merely result in us swapping one unnatural finish for another, whilst running the risk of damaging the mosaic.


The Grotto has been privately owned since its discovery and remains so today. However, it was Grade 1 listed in 1973 so Historic England watches over its preservation. The damp problem prompted English Heritage to enter it onto the Buildings at Risk register in the 1990s. Happily, the extensive conservation works carried out in recent years resulted in the Grotto being removed from the Register in 2012.


To further safeguard the Grotto, the Friends of the Shell Grotto were formed in 2008. The Friends’ group is an independent trust committed to preserving and promoting this unique Grade I listed structure.

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The Grotto has provided a fascinating backdrop in photoshoots for magazines, newspapers and book covers and we have hosted location filming for the BBC, Channel 4, ITV and many independent television companies.

If you would like to discuss hiring the Grotto please email us with an outline of your plans.

Please note that we happily allow personal photographs in the Grotto, but any commercial photography must have received written permission from us.

Photo by Dover Design Photography for Madam Popoff Vintage.

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