The Shell Grotto in Margate, Kent, is a beautiful subterranean passageway that was discovered by chance in 1835.
The chalk walls of the Grotto are covered in 4.6 million shells which have been placed to create magical mosaics, patterns and symbols.
For decades, people have debated the Grotto’s origins and purpose, with various hypotheses dating its construction to any time in the past 3,000 years.
Some experts claim the Grotto was an 18th or 19th-century rich man’s folly, while others think it was a meeting place for sea witchcraft. Others believe it is possibly connected to the Knights Templar or even Freemasonry.
However, a discovery of a domed cave in Palatine Hill, Rome, with similar shell mosaics and marble to the Shell Grotto, has led some experts to speculate that the Phoenicians could have created it in the second half of the first millennium BCE.
Some of the shells on the walls include cockles, whelks, mussels and oysters, which create beautiful patterns and symbols.
Even the Grotto’s discovery remains a mystery. Most people agree it was found at some point in 1835 but there are conflicting accounts.
The earliest mention of the discovery appears in the Kentish Gazette in May 1838, when it was announced as a public attraction.
The article described how the discovery was made. A gentleman had recently purchased Belle Vue Cottage and was making alterations to it.
One of the alterations involved excavating a few feet. The workmen carrying out the alteration came across a large rock which impeded their work. After examining the area, the discovery was made.
The Shell Grotto is open Thursday to Sunday from 11am to 4pm. Adult tickets cost £4.50, family tickets are £10 and children’s prices are £2 (aged four to 16). Children under four can enter for free.
Visitor numbers inside the Grotto are limited as it is a small, underground space, so visitors may be asked to wait before entering.