Most ‘mysterious’ walk near London with tunnels that are ‘out of this world’ (opens original article in a new tab)

A Londoner shared her experience of visiting the mysterious Shell Grotto tunnels near London, which contain 4.6 million shells and have unknown origins, now a museum open to visitors

• A Londoner shared her experience of mysterious tunnels near London called the Shell Grotto, which has 4.6 million shells and unknown origins
• The Shell Grotto in Margate, discovered in 1835, is an underground museum with passages decorated with shells and images of gods and goddesses
• The origin of the grotto remains unexplained, with theories ranging from ancient Pagan grotto to Regency folly