A network of centuries-old man-made caves has been discovered "by accident" in the small town of Royston in Cambridgeshire.
Royston Cave has become a complete mystery for locals - with no-one being able to confidently say who created them or what they were made for.
Despite conspiracy theories surrounding the caves, no records of their age or purpose exist.
Workmen accidentally found the site in 1742 and were astounded by the carvings, which mostly have links to Christianity.
An array of saints, Jesus and his disciples, Richard the Lionheart and King David of the Psalm can be seen in the markings.
A common theory about the cave is that it was owned by the Knights Templar during the Middle Ages but others believe it could have been a Freemason's Lodge.
The mysterious caves can now be visited by tourists and local historians wanting to find out more.